Replacing Woocommerce min and max price with custom field price

i have a Woocommerce e-shop and i have added a custom field for the wholesale prices. How i can get the min_price and max_price from the custome field in variable products?

i have this php script added to functions.php

add_filter( 'woocommerce_get_price_html', 'empty_and_zero_price_html', 20, 2 );
function empty_and_zero_price_html( $price, $product ) {
    global $ask_for_price;
    global $whuser;

    if($product->is_type('variable') and !is_admin()) {
        $prices = $product->get_variation_prices( true );
        if($whuser) {
            $myprice = (float) get_post_meta( $variation_id, '_pricew', true );
        } else {
            $myprice = $prices['price'];
        }

        if ( empty( $myprice) or $myprice==0 ) {
            return $ask_for_price; // <=== HERE below for empty price
        } else {
            $min_price     = current( $myprice );
            $max_price     = end( $myprice );
            if ( $min_price === $max_price && 0 == $min_price ) {
                return $ask_for_price; // <=== HERE for zero price
            }
            elseif ( $min_price !== $max_price && 0 == $min_price ) {
                return wc_price( $max_price );
            }
        }
    }
    else if($product->is_type('simple') and !is_admin()) {
        if ( '' === $product->get_price() || 0 == $product->get_price() ) {
            return $ask_for_price; // <=== HERE for empty and zero prices
        }
    }
    return $price;
}

i have replaced the $prices[‘price’] with $myprice (wholesale price) but it’s returning zero (0).

what i’m doing wrong?