4. Good negotiators can get a better price.
Get more than one bid. Start with the highest-end contractor, the best-stuff-money-can-buy guy. Ask him for a detailed proposal. Take that proposal and copy it, leaving out the costs. Pass it out to subsequent contractors you interview and ask them to fill in the costs. This will give you a good idea of what the job is worth. But be cautious: The lowest bid isn't usually the best.