There are two good knife stores I occasion. They have lots of quality knives. I would buy from them if they sold at retail. With out going into to examples, most of their knives are retail plus 15% or more. Some are unbievable. Their WH's and CRK's are in stock but make the BF secondary market look cheap. They both have been in business for a long time, so someone is buying from them.
To answer the orignal question. I would and will buy retail when that is required to get what I want, or I trust the seller and I feel I have a need to trust the seller.
For instance, I would trust a seller on BF that I recognize as an old timer even though they have no idea who I am and have never done business with me. I would assume the level of risk.
Ron Athay