I think the safe assumption is to follow the maxim "you get what you pay for". The market for new will, in an absolute sense, define quality as a function of cost. The only real deals, such as they are, are on the used market. And, they are few and far between. I once had the opportunity to acquire a pre-war Purdey 12 bore, best-quality SxS for $10,000. Some years back, I knew of a guy who bought a Holland & Holland 500/465 (again, best quality) at an estate sale in Minneapolis for around $9,000. The widow (or whoever set the price) obviously had no idea as to its worth. These things happen, but they are extremely rare. Generally a "good price" has more to do with some aspect of undesirablility - for instance, the Purdey rifle I posted, from Lewis Drake (whom you can be damn sure knows the true value of the listing). Were that rifle in another caliber, something more desirable, the price would easily double.