Pure and simple, if one is selling something, they are going to put it into the best light possible...hopefully with honesty. As you pointed out, not all Mark VI's are good horns and they come in varying conditions of playability and repair. When I see "player's horn", to me that says it is not beautiful, has been used hard and may need some work, but it is a generally good instrument that can be used in a gig. When I see "killer horn", my spidey sense tingles that it is "hype".I might be showing my natural cynicism, but how come every Mk VI for sale is a "killer" horn, a "players" horn, amazing player etc.? Bearing in mind it appears that the consensus is that there are generally some less than great VI's out there, how come there are never any of these for sale? It's irrelevant to me, as prices are at a level that I would never pay, even if I had the money. I wonder how many are so desperate to own one that they buy unplayed, and are disappointed. I have no wish to cause offence to any owners, but how refreshing it would be to read a for sale ad which described a horn as being honestly not that great, and at a price which reflected that. Maybe any VI can be made great by a skilled tech? Let the debate begin 😀!
When it comes to something like a musical instrument, I am disinclined to buy it without playing it first, period. Or I would want an ironclad agreement that I can send it back as some of the major online dealers allow but that is a pain in the neck. A friend of mine tried to sell a Mark VI alto last year and he honestly listed it as "relacquered" which brought in lowball bids- it was deemed less than great because it was a relac. But I've played that alto a few times and it is one of the best altos around. And I understand market value and all that, but I'll bet it outplays a number of original lacquer Mark VI altos out there.
My point, I am very reluctant to purchase a horn without playing it first. I am simply not astute enough to read between the lines in an ad to determine if the horn is a good deal or not.