Here are a few lines of code from a wordpress plugin (WP E-commerce) that calculate the price. Now what i want is that if 'cart_item' are more than 3 in quantity then the price should be (number of items * 4) else the function should work as it is listed below. Thnks for help. function calculate_subtotal($for_shipping = false) { 1047 global $wpdb; 1048 if($for_shipping == true ) { 1049 $total = 0; 1050 foreach($this->cart_items as $key => $cart_item) { 1051 if($cart_item->uses_shipping == 1) { 1052 $total += $cart_item->total_price; 1053 } 1054 } 1055 } else { 1056 $total = 0; 1057 if($this->subtotal == null) { 1058 foreach($this->cart_items as $key => $cart_item) { 1059 $total += $cart_item->total_price; 1060 } 1061 $this->subtotal = $total; 1062 } else { 1063 $total = $this->subtotal; 1064 } 1065 } 1066 return $total; 1067 }