I would assume no less than 200k spent on the game since this is EA....figure they had devs making 100k each a year....so 50k for 6 months. That makes 4 devs or so....bu that is a crappy estimate I just came up with. Of course, iSniper was made by one dude in a few weeks....so it's all profit for him.
You'd be shocked at how often games for 99 cents sell. Even if they don't sell enough (remember, Apple takes a small cut) it's practice for the next app. They just had some survey/study that showed that 1-2 bucks for an app made it sell a LOT better, so it could easily sell 200,000 copies. Heck, I was about to buy it!! Zombies for 99???