Welcome to The Norfolk Broads Forum
This is THE Worlds Largest Forum devoted to the Norfolk Broads, here you can discuss issues about the Norfolk Broads. Or just somewhere to chat with others interested in the Norfolk Broads area. In 2015 forum members spent 2,048 days afloat on the Broads
You could spend time and money going round other yards to get estimates, but if Boulter's is closest, why not use them. They have a very good reputation.
"..for the avoidance of any doubt, the broads are not legally a national park and do not come under the national park legislation, and nor will they." Parliamentary Under-Secretary of State for DEFRA (Hansard 2015)