You always pray the bill won't be sky high when you have no choice but to take your coach in to Prevost. On the other hand, when you have time, you have choices, so look around and talk to a few different shops and call your converter before accepting a price for repair.
Also, with knowledge comes bargaining power, so never ask a question when you don't know the answer when getting prices from Prevost. It's a good idea to know how long it shoulld take to replace a pump or fix a norgren valve.