Maybe wait for the DSi to hit the market. The Ds lite will be cheaper and you can buy it new then. (If you're looking for GBA compatibility or something)
I'm just guessing here though.
Person 1: Does Valkyria Chronicles have trophies?
Person 2: No.
Person 1: Forget it. I'm not buying it.
Person 2: Wait! It's amazing! Unique, charming, drop dead gorgeous... Hello?