[drcy]

I think in some areas, if not everywhere, it's illegal for a knowledgeable dealer to deceive a uninformed person in order to buy something too cheap, I believe there was such a case involving an Antiques Roadshow civil war expert. Got the very rare and valuable items cheap by deceiving the owner into believing the were worth much less.

In general, I think you should give a fair deal-- though a fair deal can certainly can include room for profit for you. I'm not expecting dealers to run a charity.

I also think there is a distinct difference when the seller already has a sales price and when he/she asks you for the value.

I also assume this poll is about total beginners off the turnip truck (or even not even beginners because they don't collect but found something), not antique stores who are literally licensed professionals and set the prices. What to do at an antique store or dealer's booth would be a separate poll.