I typically outsource through oDesk, It was very hard the first time but each time gets easier. The hard part is keeping decent developers. Even the good ones, you become a side project after the first one, despite increased budgets. Typically, they don't turn down work and you suffer instead of them telling you to wait a month and risk losing you. I have had a simple crappy app made for $75 all they way up to a few grand. Typical release ready non-game app can be had around $750. Games apps can be all over the place as far as development costs.