edit: Apparently the item from my transaction was in my inventory, I had checked multiple times and guess I still managed to miss it. I'm really sorry about any concerns I may have caused due to that. HOWEVER I would still be wary of
I'm not sure if this will happen to you if you do, but there seems to be a bug affecting transactions where the items/currencies are eaten up into non existance, this had just happened to me(invalid, my mistake, check above edit), and it seems to have happened to another user (still should be wary of).
I think it's important for this issue to be known to users, I would hold off on gifting items/doing trades via messages until it's addressed! I really hope this is dealt with as soon as possible, it's very concerning.