$150/hr for a good developer means this thing can run for a year and still be cheaper. Any improvements or enhancements they add you basically get for "free" over that time.

Plus, I have yet to see the feature that requires coding once and never needs touching again. When I upgraded my app from Rails 2 to Rails 3, there were all sorts of 1-offs like this that I had to tweak and fiddle to get working right again. It takes well over an hour just to remember what you were thinking when you originally wrote it.