Like many others I have found the coin trade in system to be very frustrating. With Iron banner I have been trying to collect the whole armor set and over 20 trade ins later I'm still missing the chest piece. I have gotten the helmet 5 times and the legs multiple times as well. I don't feel that the current trade in system is overall bad I feel like some changes would make it much less frustrating though. For example of there was a way for the game to track the gear you have already received and cut the drop percent on those pieces making it more likely to recieve the ones not recieved yet. Then once you have recieved all the gear maybe have it reset to the normal drop rates again and cycle through like that.