WooCommerce 2.4 – Price cache workaround - Dynamic key

woocommerce_custom_product_price_cache_key1.php

/**
 * Alters the key used to store cached prices. This code snippet allows 
 * to use dynamic cache keys, thus making it possible to store multiple
 * sets of prices in the cache.
 * You can add this code to the functions.php file in your child theme
 * folder, or to a custom plugin.
 * 
 * @param array cache_key_args The arguments that form the cache key.
 * @param WC_Product product The product for which the key is being generated.
 * @param bool display Indicates if the prices are being retrieved for display
 * purposes.
 * @return array
 * @since WooCommerce 2.4
 * @author Aelia <support@aelia.co>
 * @link http://aelia.co/2015/08/11/wc-2-4-workaround-for-price-cache
 */
function set_custom_price_cache_key($cache_key_args, $product, $display) {
  // This is an example. You would have to implement your logic 
  // to determine if the customer is a wholesaler
  $customer_is_wholesaler = my_custom_function();

  // We add the "wholesaler" flag to the element that constitute the
  // cache key. This will create two cached copies of the product prices:
  // - One price list for wholesaler
  // - One price list for non-wholesaler
  // The appropriate copy will be retrieved automatically.
  $cache_key_args[] = (string)$customer_is_wholesaler;
  return $cache_key_args;
}
add_filter('woocommerce_get_variation_prices_hash', 'set_custom_price_cache_key', 10, 3);