That's what I am doing except I think I will just get a Wii U when I can afford it. I guess I am another $150 away using that gift card and the $115 I have lol.
It's always shitty to get rid of games.. before I went in I have 47 games on my shelf.. Out of those I play/will play maybe 5 of those. Now I am left with 27 or so. The only reason I wont trade in the others is because they are either gifts or will only get me $1. Hell, tried to trade in NHL 10, NBA 2k10 and The Bigs but they said they don't have a value for them. I offered them free and they said they couldn't.
As long as you play those games, keep them. If not, consider trading them.