How to calculate and update sales price in woocommerce product page

I inserted two radio buttons as product add ons by using the following to calculate extra packaging cost. But I have two problems.

First instead of getting the value of my custom field eg 4.35 it gets a value of 4.00.

Second how can I update the sales price in my product page when I choose an option

function add_custom_fees_before_add_to_cart() {
    global $product;

    $myfee = floatval(get_post_meta(get_the_ID(), '_skrprom', TRUE)) + floatval(0.90);

    $args = array(
        'type' => 'radio',
        'class' => array( 'form-row-wide' ),
        'options' => array(
        '' => 'Τηλεφωνική Παραγγελία',
        $myfee => 'Έξοδα Συσκευασίας '.$myfee.'€',
    ),
    'default' => ''
);
?>
<div class="custom-fees-wrap">
    <label for="iconic-engraving"><?php _e( 'Customize Your Order!', 'textdomain' ); ?></label>
    <?php woocommerce_form_field( 'custom_fees', $args, '' ); ?>
</div>
<?php
}

add_action( 'woocommerce_before_add_to_cart_button', 'add_custom_fees_before_add_to_cart', 99 );


function save_value_add_cart_item_data( $cart_item_data, $product_id, $variation_id ) {
$custom_fees = filter_input( INPUT_POST, 'custom_fees' );

if ( empty( $custom_fees ) ) {
    return $cart_item_data;
}

$cart_item_data['custom_fees'] = $custom_fees;

return $cart_item_data;
}

add_filter( 'woocommerce_add_cart_item_data', 'save_value_add_cart_item_data', 99, 3 );

function calculate_add_cart_fee() {
   global $woocommerce;
   $cart_items = $woocommerce->cart->get_cart();
   foreach( $cart_items as $key => $item ) { 
      if( !isset( $item['custom_fees'] ) && empty( $item['custom_fees'] ) ) continue;
    $woocommerce->cart->add_fee( __('Έξοδα Συσκευασίας', 'textdomain'), $item['custom_fees'] );
}
}
add_action( 'woocommerce_cart_calculate_fees', 'calculate_add_cart_fee', 99 );