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

Overhead? What's overhead? Smdh

Don't like their business model don't use it, or you just want to bitch? 

They also offer to sell your gear for you with their consignment program. Should you prefer that. 

Sold a couple REL subs through consignment with TMR. The process was painless and I netted an amount that is good enough considering what I originally paid for them.

TMR doesn’t get consigners top dollar but it does list items at above typical market value. Apparently there are many willing to pay a premium for that option to return an item. 

TMR is a business that provides a service of selling for you, so I’d expect it’s more expensive than selling yourself.  This service is not free, and many use their services.  

My only issue with TMR is their rating practices.  They tend to overrate the condition of their gear.  For instance, they will routinely list gear for sale on Audiogon rated as 9/10 and then describe said gear as very good but go on to show marks on the face of amps or front baffles of speakers.  So their 9/10 is my 7/10.  As such, I look very, very carefully at their pictures and take their overall “condition” with a giant grain of salt.  Basically, I don’t consider buying anything from them unless it is “exceptional” and even then I have received one item before that had a mark (albeit small) on the top plate despite being described as exceptional.  YMMV