The thing is, that's all you can ask for or you look like a scam artist or an idiot because you're over-asking. People, for better or worse, take into account how much you're asking for relative to what you promise, and fund or don't fund based on that.
The unfortunate thing about game development Kickstarters is that the worst thing that can happen is that you make exactly your goal.
If you ask for $5000. Chances are you're going to get closer to that, than $50,000. If you ask for $500,000. Chances are you're going to get higher than the $5,000.