Question on Benz Trade-Ins

Yes, I understand this TVAD, I actually paid less than what the "commonly listed" trade-in program allowed, and this was from the Benz dealer in which I bought my previous Benz from. (So it was all legit)

I was the original owner of the trade-in cartridge, so this still leaves me unsure what the scoop is if I were to buy a used, dead Cartrdge from let's say an agon seller who was perhaps the original owner?

Also, I'm not referring to buying from online agon sellers, who may not actually be a recognized Benz Dealer, or from overseas. In these particular circumstances, one might get a swell deal, but in this scenario, I'm not so sure one has any warrantee to speak of? Mark

I know a dealer that will take any cart from Benz or Clear Audio but that may be a benefit to his loyal customers and not really the normal practice or it could be just up to the dealer to decide what he wants and doesnt want to do.