If I trade in my dsi today will I still get 75$ off for the nintendo 3ds?

I want to get 2 3ds for my children but I want to trade their dsi's for it. I heard that if I trade in a dsi fro a 3ds you get 75$ off. Do I still get this amount off? Or is it expired? Also how much money would I get if I trade in these games: Spiderman 2, Asphalt urban gt, Atv quad frenzy. Oh and how much do I get for each GBA game I trade in?