What's funny about what you said, Josh K, about this not being an auction block, is that the way you want to do things is how some auctions work, like eBay. Bidders remain confidential. Some get stuff for a song, then turn around and post it for sale at a higher price. Those types of folks don't even like posting/exchanging feedback because it would make it easier for others to trace an item and see what the seller got it for, etc... .
What I meant by auction site is that you do not have any compulsion to sell to the person who says "I'll take it." first or wishes to pay the most. That's all.
What is wrong with buying a knife cheap and flipping it? Have a Dealer membership? Go for it buddy. What is this, some kind of anti-capitalism soapbox speech? One of the most prominent Busse dealers engages in the behavior you explicitly define, yet people seem to not have an issue buying or selling with him.