DW:Gundam 2 is coming at the end of March. I would assume that it would have everything the original has plus some improvement/additions. So unless you're into the weak-ass story they slapped onto the original, I'd wait.
What's curious though is that even though the new game is on the horizon, the original is still pricey.
Plus, where's all the pre-order deals for the sequel? I haven't seen any, have you guys?