From the announcement:
Due to popular demand, we are happy to introduce a new bulk buy discounting system available through our webshop. Get together with your friends or go crazy yourself to take advantage of larger discounts. We hope that this system helps out our overseas buyers to offset (or completely erase) postage costs. As a result of this change, Value and Combo packs are no longer available. Discounts are calculated based on the value of the products in your cart. Remember to change the currency to view discount levels and prices in your local currency.