Dave,
If the bid is detailed, I would fax it around and see if you can get bids off of it. I was had a job recently and bids went from over $250 to the $100.00 I finally paid. The work only took about 15 minutes but getting anyone to come out for a small job was hard. Despite being over priced, they all seemed to have a week lead time. Makes me wish I was a plumber.