Show Price along with WooCommerce variation in drop-down.

price-with-variation-in-dropdown.php

<?php
add_filter( 'woocommerce_variation_option_name', 'ab610_display_price_in_variation_option_name' );

function ab610_display_price_in_variation_option_name( $term ) {
    global $wpdb, $product;

    $result = $wpdb->get_col( "SELECT slug FROM {$wpdb->prefix}terms WHERE name = '$term'" );

    $term_slug = ( !empty( $result ) ) ? $result[0] : $term;


    $query = "SELECT postmeta.post_id AS product_id
                FROM {$wpdb->prefix}postmeta AS postmeta
                LEFT JOIN {$wpdb->prefix}posts AS products ON ( products.ID = postmeta.post_id )
                WHERE postmeta.meta_key LIKE 'attribute_%'
                AND postmeta.meta_value = '$term_slug'
                AND products.post_parent = $product->id";

    $variation_id = $wpdb->get_col( $query );

    $parent = wp_get_post_parent_id( $variation_id[0] );

    if ( $parent > 0 ) {
        $_product = new WC_Product_Variation( $variation_id[0] );
        return $term . ' (' . woocommerce_price( $_product->get_price() ) . ')';
    }
    return $term;
}