> Would you happily buy that at say, 50% MSRP?

Yup, assuming it works and checks out the first 24 hours I have it.

Solid state electronics are pretty robust. If they survive whatever torture you put them through plus being shipped to my door, chances are it will work just fine. In my experience there are some problematic GPU models that are more prone to early failure under heavy use (HD6990 I'm looking at you!), but they are more rare than legend may lead folks to believe.

At an appropriate discount it's far cheaper to just buy these at pennies on the dollar and just be alright with self-insuring for a rather rare early failure. When you can buy 2 or 3 for the price of new, it starts to get rather compelling.

As long as there isn't any corrosion that will lead to premature failure, I don't care. Dust is easy to clean off and I would expect anyone trying to sell a $500+ GPU to at least try to clean it up a bit. Even if not, I have an air compressor and a blow gun. "Energy fluctuations"...what? Power supplies and VRMs are built to deal with this. Check your home with a power analyzer with a high sampling rate and see what happens when your AC kicks on. At the same time, measure the 12v rail going into your GPU when that's happening.

How do you tell there's no corrosion though? You need to at the very least take off any coolers on the card and look at the PCB itself to have some level of confidence that there's no damage, and even then I've seen corrosion sneak under components where you need to pay really close attention to notice it.

If I can inspect a card in person, I would be plenty happy to buy an ex-mining card, but most of these are going to be sold online sight-unseen. This isn't a problem exclusive to mining cards though; people have been selling damaged GPUs as 'working' for years.

Yes.

same