How Much Does It Cost to Develop a Good iPhone Application?
stackoverflow.com/questions/209170/how-much-does-it-cost-to-develop-an-iphone-application
From the page
Saved with the link. Notes from 2007 to 2016 are mostly the page's own words, so this is probably an excerpt.
Craig Hockenberry makes the case that it can run at least a few hundred thousand dollars.