So... is it a Chris Craft or a Formula?
(A scarab would have been 30' you said 31)
Off the top of my head I would say that you are looking at 7 or 8 thousand if you have them do the whole job. 3 or 4 thousand if they only do the glass work.
Unfortunately... the boat needs to be un-rigged and re-rigged.
Add a couple thousand if your stringers are really bad.
There are a couple great threads on the subject. Big job.