Woocommerce variable product, include price with attribute name in variation dropdown.

theme_functions.php

<?php

// For changing Option Name of variable product on Front end, including price with attribute name
add_filter( 'woocommerce_variation_option_name', function($option, $null, $attribute, $product){
    if($product instanceof WC_Product_Variable){
        $variations = $product->get_available_variations();
        foreach ($variations as $key => $value) {
            if(isset($value['attributes']['attribute_volume']) && isset($value['display_price']) && $value['attributes']['attribute_volume'] == $option){
                $option = $value['attributes']['attribute_volume'].' - Rs.'.$value['display_price'].'/-';
            }
        }
    }
    return $option;
}, 11, 4);