Hmm I'm not really into this. Imagine, you see someone coming and you have 20 diamonds and it's OP, you quickly buy full iron and kill him. Once you've done that you can easily farm diamond again, but in reality you're carrying 20 diamonds worth of armour and maybe a sword. This means less diamond farming = faster gear = more rushers and early campers, and those are 2 things half of the community complain about. For some reason I find this hard to explain, but I hope you get my point. You can always refund the good gear you had, while still being stacked. I feel like if this gets added (but I'd rather keep it out of the game), the idea of only being able to refund if it's undamaged + if it's only bought by you + a lower refund reward (maybe 20% of the initial price) should balance this feature and shouldn't give much of an advantage/abuse.