Ah, Janie: It's beginning to sound like your quote was to replace the whole roof. Maybe get yourself a building inspector and have him do a complete house inspection, just as though you were selling it.
If he is any good, he'll give you everything you need to take to the contractors who will in turn, give you your cost estimate.
When you get that far, come back in and we'll give you some pointers with regards to hiring contractors.