And there in lies the auction conundrum. Where one may be willing to take a price, say $500, from an individual buyer, they're also unwilling to risk it selling for a lower reserve price at auction even when there's a chance it may sell for much, much more than the price they're willing to accept from the individual buyer - even after the auction surcharge.
I used to work in wine auctions so I know the game intimately.
However, here's something most sellers don't know/consider: if they have a pristine collection and pit the auction houses against one another, consignment fees are frequently waived.
Hence my point, if you have some patience, a great collection and really understand the game, the auction market can be really great for your returns - even considering possible fees.