How to get custom variable price if bought in bulk (2x, 3x)

I want to have option to buy 2x or 3x product with discount (custom) price.
If chosen 2x or 3x all the attributes have same price.

The issue is that the custom price (e.g., 19.9) is not being applied to the cart item, and the base prices (price: “22.90”, regular_price: “34.90”) are still being used. This indicates that the custom price is not being properly passed to the server or applied to the cart item.

1. Custom Price Not Applied:
   The custom price is sent to the server, but it is not being applied to the cart item.
   The base prices (price, regular_price, sale_price) are still being used.

2. WooCommerce REST API Not Handling Custom Price:
   The WooCommerce REST API (/wp-json/wc/store/v1/batch) does not natively support custom prices. You need to handle this on the server side.

3. JavaScript and PHP Integration:
   The JavaScript code sends the custom price to the server, but the PHP code is not properly applying it to the cart item.

To solve this problem, i need to:

1. Ensure the Custom Price is Passed to the Server:
   The JavaScript code must send the custom price to the server when adding items to the cart.

2. Apply the Custom Price to the Cart Item:
   Use WooCommerce hooks to override the product price when it is added to the cart.

3. Retain the Custom Price in the Cart Session:
   Ensure the custom price is retained in the cart session after page refresh.

4. Display the Custom Price in the Mini-Cart and Cart Page:
   Ensure the custom price is displayed correctly in the mini-cart and cart page.

My functions code:

function custom_pricing_options_html() {
    if (!is_product()) return;

    global $product;

    // Check if the product is simple or variable
    if (!$product->is_type('simple') && !$product->is_type('variable')) return;

    $product_id = $product->get_id();
    $currency = get_woocommerce_currency_symbol();

    // Get base prices
    $regular_price = $product->is_type('variable') 
        ? floatval($product->get_variation_regular_price('min')) 
        : floatval($product->get_regular_price());
    $sale_price = $product->is_type('variable') 
        ? floatval($product->get_variation_sale_price('min')) 
        : floatval($product->get_sale_price());

    // Get custom pricing options from ACF fields
    $price_option_2 = floatval(get_field('pricing_option_2', $product_id)) ?: 0;
    $price_option_3 = floatval(get_field('pricing_option_3', $product_id)) ?: 0;

    // Pricing options for 1x, 2x, and 3x
    $pricing_options = [
        1 => ['price' => $sale_price],
        2 => ['price' => $price_option_2],
        3 => ['price' => $price_option_3],
    ];

    ob_start();
    ?>

    <div class="pricing-container">
        <?php foreach ($pricing_options as $qty => $option) :
            if ($option['price'] <= 0) continue; // Skip empty values
        ?>
        <div class="pricing-option <?php echo $qty === 1 ? 'selected' : ''; ?>" 
            data-qty="<?php echo esc_attr($qty); ?>" 
            data-price="<?php echo esc_attr($option['price']); ?>" 
            data-currency-symbol="<?php echo esc_attr($currency); ?>">
    
            <div class="qty-discount-qty"><?php echo esc_html($qty); ?>x</div>
            <span class="qty-discount-price">
                <strong><?php echo esc_html($option['price'] . ' ' . $currency); ?></strong>
            </span>
            <div class="qty-discount-kos">per pair</div>
        </div>
        <?php endforeach; ?>
    </div>

    <!-- Hidden field to store the selected price -->
    <input type="hidden" id="custom_selected_price" name="custom_selected_price" value="<?php echo esc_attr($sale_price); ?>">
    
   
    <?php
    echo ob_get_clean();
}
add_action('woocommerce_before_add_to_cart_form', 'custom_pricing_options_html');

// Save the selected price in cart item data
add_filter('woocommerce_add_cart_item_data', 'update_sale_price_in_cart', 10, 2);
function update_sale_price_in_cart($cart_item_data, $product_id) {
    if (isset($_POST['custom_selected_price'])) {
        $selected_price = floatval($_POST['custom_selected_price']);
        error_log('Selected Price in Cart: ' . $selected_price); // Debug
        $cart_item_data['custom_price'] = $selected_price;
    }
    return $cart_item_data;
}

// Apply the custom price to the cart item
add_action('woocommerce_before_calculate_totals', 'apply_custom_price_to_cart', 20);
function apply_custom_price_to_cart($cart) {
    if (is_admin() && !defined('DOING_AJAX')) return;

    foreach ($cart->get_cart() as $cart_item_key => $cart_item) {
        if (isset($cart_item['custom_price'])) {
            $custom_price = floatval($cart_item['custom_price']);
            $cart_item['data']->set_price($custom_price); // Override base price
        }
    }
}

// Retain the custom price in the cart after page refresh
add_filter('woocommerce_get_cart_item_from_session', 'retain_custom_price_in_cart', 10, 2);
function retain_custom_price_in_cart($cart_item, $values) {
    if (isset($values['custom_price'])) {
        error_log('Retaining Custom Price: ' . $values['custom_price']); // Debug
        $cart_item['custom_price'] = $values['custom_price'];
    }
    return $cart_item;
}

// Display custom price in mini-cart and cart page
function display_custom_price_in_cart($price, $cart_item, $cart_item_key) {
    if (isset($cart_item['custom_price'])) {
        $price = wc_price($cart_item['custom_price']);
    }
    return $price;
}
add_filter('woocommerce_cart_item_price', 'display_custom_price_in_cart', 10, 3);
add_filter('woocommerce_cart_item_subtotal', 'display_custom_price_in_cart', 10, 3);

// AJAX Handler for Adding to Cart with Custom Price
add_action('wp_ajax_add_to_cart_with_custom_price', 'add_to_cart_with_custom_price');
add_action('wp_ajax_nopriv_add_to_cart_with_custom_price', 'add_to_cart_with_custom_price');
function add_to_cart_with_custom_price() {
    if (!isset($_POST['product_id']) || !isset($_POST['custom_price'])) {
        wp_send_json_error('Invalid request.');
    }

    $product_id = intval($_POST['product_id']);
    $quantity = intval($_POST['quantity']);
    $custom_price = floatval($_POST['custom_price']);

    // Add product to cart
    $cart_item_key = WC()->cart->add_to_cart($product_id, $quantity);

    if ($cart_item_key) {
        // Set custom price in cart item data
        WC()->cart->cart_contents[$cart_item_key]['custom_price'] = $custom_price;
        WC()->cart->set_session();

        // Recalculate totals to apply the custom price
        WC()->cart->calculate_totals();

        wp_send_json_success('Product added to cart.');
    } else {
        wp_send_json_error('Failed to add product to cart.');
    }
}

My javascript:

jQuery(document).ready(function ($) {
    const $body = $('body');
    const $pricingOptions = $('.pricing-option');
    const $customSelectedPrice = $('#custom_selected_price');
    const $addToCartButton = $('.single_add_to_cart_button');

    // Event delegation for pricing options
    $body
        .on('click', '.pricing-option', function () {
            $pricingOptions.removeClass('selected');
            $(this).addClass('selected');

            const qty = $(this).data('qty');
            const price = $(this).data('price');

            // Debug: Log the selected price
            console.log('Selected Price:', price);

            // Update the hidden input field
            $customSelectedPrice.val(price);

            duplicateVariationSelection(qty);
            updatePriceTotal();
            updateSimpleQuantity(qty);
            maybeDisableVariableAddToCartButton();
        })
        .on('click', '.qty-appended .filter-item-list li', function () {
            $(this).parents('.qty-appended').find('.filter-item-list li').removeClass('active');
            $(this).addClass('active');
            maybeDisableVariableAddToCartButton();
        })
        .on('click', '.product-type-variable .single_add_to_cart_button', function (e) {
            e.preventDefault();

            const selectedPrice = $customSelectedPrice.val();
            console.log('Price sent to server:', selectedPrice);

            if ($(this).hasClass('wc-variation-selection-needed') && $('.qty-appended').length > 0) {
                alert('Please select all variations before adding to cart.');
                return;
            }

            addAppendedItemsToCart(selectedPrice);
        });

    // Duplicate variations based on selected quantity
    function duplicateVariationSelection(qty) {
        if ($('.product-type-variable').length <= 0) return;

        const label = $('.variations .label label').first().text();
        const list = $('.variations .value ul.filter-item-list').clone().html().replace(/active/g, '');

        $('.qty-appended').remove(); // Remove previous appended rows

        for (let i = 2; i <= qty; i++) {
            $('.variations tbody').append(`
                <tr class="qty-appended qty-${i}">
                    <th class="label"><label>${label} ${i}</label></th>
                    <td><ul class="filter-item-list">${list}</ul></td>
                </tr>`);
        }

        maybeDisableVariableAddToCartButton();
    }

    // Enable/disable the "Add to Cart" button based on selected variations
    function maybeDisableVariableAddToCartButton() {
        const totalAppended = $('.qty-appended').length;
        const totalSelected = $('.filter-item-list li.active').length;

        $addToCartButton.prop('disabled', totalAppended + 1 !== totalSelected);
    }

    // Add items to the cart
    function addAppendedItemsToCart() {
        const attributeName = $('[data-attribute_name]').data('attribute_name');
        const variationData = $('[data-product_variations]').data('product_variations');
        const totalAppended = $('.qty-appended').length;
        const selectedPrice = $('.pricing-option.selected').data('price'); // Get selected price
        let cartData = [];
    
        let itemAttributeOriginal = $('table.variations tr:not(.qty-appended) li.active a').data('value');
    
        // Original selected variation.
        $.each(variationData, function (key, value) {
            if (value['attributes'][attributeName] === itemAttributeOriginal) {
                cartData.push({
                    path: '/wc/store/v1/cart/add-item',
                    method: 'POST',
                    headers: {
                        'Nonce': product_js_vars.woononce
                    },
                    body: {
                        id: value.variation_id,
                        quantity: 1,
                        custom_price: selectedPrice // Include custom price
                    }
                });
            }
        });
    
        // If multiple appended
        if ($('.qty-appended').length > 0) {
            for (let i = 1; i < totalAppended + 1; i++) {
                let counter = i + 1;
                const itemAttribute = $(`.qty-${counter} .filter-item-list li.active a`).data('value');
    
                $.each(variationData, function (key, value) {
                    if (value['attributes'][attributeName] === itemAttribute) {
                        cartData.push({
                            path: '/wc/store/v1/cart/add-item',
                            method: 'POST',
                            headers: {
                                'Nonce': product_js_vars.woononce
                            },
                            body: {
                                id: value.variation_id,
                                quantity: 1,
                                custom_price: selectedPrice // Include custom price
                            }
                        });
                    }
                });
            }
        }
    
        $.ajax({
            url: '/wp-json/wc/store/v1/batch',
            method: 'POST',
            dataType: 'json',
            headers: {
                'Nonce': product_js_vars.woononce
            },
            data: {
                requests: cartData
            },
            success: function (response) {
                console.log("Items added to cart:", response);
            },
            error: function (xhr) {
                console.error('Error adding item to cart:', xhr.responseJSON);
            }
        });
    }

    // Update the displayed price
    function updatePriceTotal() {
        const selectedOption = $('.pricing-option.selected');
        const price = selectedOption.data('price');
        const qty = selectedOption.data('qty');
        const percent = selectedOption.data('percent');
        const regular = selectedOption.data('regular');
        const currency = selectedOption.data('currency-symbol');

        const totalRegular = (regular * qty).toFixed(2);
        const totalPrice = (price * qty).toFixed(2);

        $('.price-placeholder').html(`
            <div class="variable-price-box">
                <div class="left-price-wrapper">
                    <div class="limited-offer-label">Quantity: ${qty}</div>
                    <div class="discount-badge-price">-${percent}% discount</div>
                </div>
                <div>
                    <del>${totalRegular} ${currency}</del>
                    <ins>${totalPrice} ${currency}</ins>
                </div>
            </div>`);
    }

    // Update quantity for simple products
    function updateSimpleQuantity(qty) {
        if ($('.product-type-variable').length > 0) return;
        $('form.cart .quantity input.qty').val(qty).trigger('change');
    }
});