Thanks for letting us know! There's definitely something very weird going on here but I'm having trouble narrowing down exactly what's broken. Can you let me know exactly what options you're picking in the shop (ie, "buy paid services, random user, premium paid account for 6 months") and what happens when you do it? (ie, "I hit 'add to cart' and it doesn't actually add the item to the cart") Right now I can only identify one pathway that's definitely busted (buy paid time, for random user, any item, add to cart: item gets discarded and doesn't go into the cart) -- I've tested "for yourself" and "for another user" and they work for me, but if you let me know the exact steps you're taking it will help us figure out the problem.

EDIT: okay, we narrowed down what we thought was causing the problem and reverted the change until we can figure out what the issue is and why it didn't show up in testing. I have verified that you should be able to buy paid time now and I'm sorry for the inconvenience!