It wasn't clear in my first comment, but it is representative of a company, not an individual. We're fortunate to have a great team estimating and scoping projects and great developers on staff staying on budget; it's rare that our actual rate is less than what I've cited, and we don't cut scope to stay on budget. Estimating, by far, is the hardest part.
If the app isn't to our internal standards, we'll do whatever it takes to get there, even if it pushes us over budget (ie, staying up until 4am).
Ok, I think this is a big point of confusion. A "company" rate is very different than a developer rate. A company rate usually includes project managers, client liaisons, secretaries, etc. I can't imagine an individual developer getting paid $20,000 for one month of 40-hour-per-week iPhone work.
I think it's important that we make this clear to new developers, so thanks for clearing it up.
If the app isn't to our internal standards, we'll do whatever it takes to get there, even if it pushes us over budget (ie, staying up until 4am).