I'm a little perplexed/surprised by TMR and who sells to them.....

TMR tells you upfront what they plan to sell it for, and how much they will send you on direct sale to them, or after sale on consignment. Then you decide ...

This. 

To the butthurt crowd - perhaps you own stocks? If you do, then you know that you sell at bid and buy at ask. The difference between the two - the spread - is where your broker makes their money. TMR is a hifi broker, and of course the spread is much wider, because hifi is a very illiquid commodity.

Whatever you’re getting from TMR is fair. If you don’t like the 10 cents on the dollar you’re getting for 15-year-old wired 4 sound or NAD trash, next time try McIntosh or Boulder or Burmester instead.

Two individuals come to a price agreement, the buyer and seller exchange assets.

What value does “outside observers” scrutinize the transaction for judgment of fairness?  

I recently consigned a phono  stage with TMR and it was a good experience.

TMR Advised on pricing and gave me the choice of consigning the item or selling it to them outright. My equipment sold pretty quickly, and I had my money within a few days of the sale. The commission is pretty steep and maybe I could have made a little more selling it myself. It was worth the commission to me to know that once the equipment sold and I had my money it was done . Any hassle with the buyer, Shipping issues, etc., was not my problem. So, it was worth it to me and my experience was good. 

I’ve had many purchases from TMR, all good in the end. A few of my favorite acquisitions have come though them. Their stock list is excellent and they’re definitely taking market share away from other secondary sales sites - rightfully so, in many cases. I check their "Fresh Arrivals" regularly, and think they provide a very nice service to us audiophiles. 

You do pay a premium with TMR, but on the other hand they pack gear PROPERLY, ship FAST, and offer recourse if needed. Their ingress / egress is a well oiled machine. 

I did once get a set of used Tannoys from TMR which sounded awful. I started processing a return but they gave me some pushback about "room positioning" and "amp matching", as if I was a freshly born babe with no clue how to hook up a system - not that they weren’t going to process the return, but they were going to burn some time on trivial matters getting there. It was definitely not a "no questions asked" process. Anyways, I was getting frustrated, and decided I’d just replace the drivers myself at some point. So I kept them. A few years later, when I finally got around to popping out those drivers - I was surprised to see they were wired VERY incorrectly (not just inverted phase; it was a real clusterf*ck bridging the tweet and woofer incorrectly)! And it was done the same (wrong) way for both L and R speakers. Funny how that made it though their testing procedues - I can guarantee they sounded AWFUL and would measure like crap. Anyways, wiring now fixed (simple), the original drivers were FINE and sounded awesome. I was very pleased with the purchase, in the end. But it did make me think "lol" about their testing and pushback (at NO point did they suggest checking the internal wiring). Seems that was just a 1-off blip. Almost everything else I’ve received from them has been perfect. 

Now if I encounter a Tannoy that sounds bad, I check the wiring first - that’s easy to fix (their fast-on shoe connectors can also pop off sometimes, just from acoustic energy in the cabinets). Unfortunately sometimes it’s the crossover at fault.