find

$price = $wpdb->get_var("SELECT `price` FROM `".WPSC_TABLE_VARIATION_PROPERTIES."` WHERE `id` = '{$priceandstock_id}' LIMIT 1");

change to this

$variation_data = $wpdb->get_var("SELECT `price` FROM `".WPSC_TABLE_VARIATION_PROPERTIES."` WHERE `id` = '{$priceandstock_id}' LIMIT 1");
	      $product_data = $wpdb->get_row("SELECT `price`,`special`,`special_price` FROM `".WPSC_TABLE_PRODUCT_LIST."` WHERE `id`='".$product_id."' LIMIT 1",ARRAY_A);
	      
	       if(($product_data['special_price'] > 0) && (($product_data['price'] == $variation_data) >= 0) && (($variation_data - $product_data['special_price']) >= 0) && ($no_special == false)) {
	         $price = $product_data['special_price'];
	       } else {
	         $price = $variation_data;
	        
	       }

Sale Price/Variation custom
this code just work if all variation price is a same as product price

WP-Ecommerce - processing.functions.php

wordpress

PHP