Personally; I've only been faced with 2nd hand component problems twice. Both surfaced shortly after purchase, one with a TacT RCS 2.2X and the other: an Audio Magic Stealth XXX. When I called the companies, requesting repair estimates, both offered to cover the repairs under warranty, based on the serial numbers/component age(I still own both). YES; companies yet exist, that care about their customers.
Hostility from manufacturers
I know its a cottage industry, and margins are thin, but I still think its shortsighted of them, and harms the industry in the long run. I'm talking about several interactions I've had with manufacturers after having purchased their products on the secondhand market. They should think about what would happen to their prices and their sales if their products were not resellable. Maybe they would like us to send our components to the scrap heap every few years or so just before we purchase their latest upgrade.
Fire away..
Fire away..