The better contractors on elance will guarantee you an hourly rate for changes too. In my limited experience, they seem pretty reasonable about it. It's of cour

The better contractors on elance will guarantee you an hourly rate for changes too. In my limited experience, they seem pretty reasonable about it. It's of course impossible to say whether they're over-billing, but it sure never felt like they were, and the rating system gives them a vested interesting in ensuring that.