AK Move In Question

[David Sklansky]

Forgive me if this has been discussed before.

Nine handed 25-50 game with typical players for those stakes. They all have you covered. Early position brings it in for 200. Three callers. You have AK in the big blind.

Obviously with any kind of shortish stack you would move in. My question is how big does that stack have to be before you would seriously consider not moving in? And how would being suited change your answer?