Shipping and packaging costs continue to increase, and we cannot continue to pay more for shipping than the amount of your sample purchases. For that reason, we instituted a minimum purchase amount of $ 5.00 for US orders and $25 for international orders. This means that if you place an order below the minimum, it will be cancelled and refunded. If you want a single sample (or just a few samples internationally), you can ask to be billed for the shipping charges, but this would probably be less cost-effective for you than buying a few samples or one of the multi-sample packs.
On all US purchases above the minimum, we will continue to offer free US shipping for the foreseeable future.