lol I wish I could, but if I did that, he would know what his gift is. I've been trying to think of clever ways to take it away without suspicion, but he hasn't given me reason too. Oh well, just hoping the value holds.
I've been here before and I'm sympathetic to this as a fellow parent: if you give the big gift early, it's nearly impossible for your kid to not feel disappointed on the actual holiday when they don't have the big present to open. It's not about being spoiled either, its just hard for kids...because they are kids.
You'll still get something for the trade in if the value drops, just less. I'm guessing its probably worth the potential loss.