I'm about to place an order and I was thinking maybe someone would like to trade STP's with me? Someone who is thinking of placing an order in the near future? Hurry up and answer

Last wednesday I made an order that still hasn't been shipped off. And now it's monday again and I have a hunch that a favourite of mine will be printed. Is there a posibility that I could mail threadless and have them merge a new order with my old one? Like ship them in the same package to save some shipping costs?

I don't feel like canceling my old order to place a new one since half of the shirts in the old order are sold out and I'm afraid of losing them. And also I don't feel like placing an order with just one shirt, since I live in Sweden and the shipping is expensive. Anyone ever been in this situation?