Yes, that’s good indeed for you as a buyer. Imagine what the schmuck that sold the 20K amp to TMR got for it. I’m guessing 4-5K.
The real point is, TMR sold the amp for $8K, and TMR commands a premium over individual sellers, so if TMR got $8K for it then the schmuck, as you kindly put it, might have gotten $6K or $7K selling it on his own.
Therefore the "schmuck" was schmucked not by TMR but by his paying $20K for an amp no one wants.
Had he spent the same $20K on a McIntosh, the numbers would look very different.