Eleanor,
Getting three very different price quotes is exactly what I'd expect. Think of it this way. You have a parent company that owns Nordstrom's, J C Penny and WalMart. You go shop for a silk scarf and find they are $250, $95 and $45 respectively. Make sense?
Moorings is considered the top tier company with the newest nicest boats. Sunsail is a step down now with Footloose bringing up the bargain basement of older boats.