I used Dan Jacobs from Durham a number of years ago, and he was great. Don't have contact info, but if he's still around, you should be able to find him for a quote. I recall price depended on three factors - if you had to, or wanted to, take off the old shingles; the type of shingles you use, i.e., 15 year or 30 year architectural, e.g.; and contractor labor.
Beyond price, talk to past customers about the job site, or try to drive by a current job site. Depending on your pickiness, it can really matter whether someone cleans up at the end of each day, or leaves crap all over your yard.
Good luck w/ the job. A new roof can really improve a home's attractiveness.