hi Suzan! You know, many places count on people not shopping around. I once had a bid to paint the trim on my house that was twice as expensive as the finished cost of a new bathroom with marble tile and kohler fixtures. They don't need to get all the jobs, just a couple. Nice truck though!
I'd do a couple of things if you are really confused- 1) ask the expensive company why they are more expensive 2) ask the less expensive company how they are able to be so "competitive"- and then ask for references that you can personally call. You may find that while the service was good the more expensive bid includes better prep work or after care. They might warrant their work longer. Then again, they might just charge more.
Not everyone is a good business person- many small businesses undercharge for their services, because they don't think people will pay the higher prices. Unfortunately, the psychology of pricing indicates that people place more value on more expensive goods.
Kelly