A lot of hate around here but having mined and still have my ex mining cards (I don't tend to sell anything really...) but still, I can say hand on heart that mining on cards doesn't really put as much strain on them as people think depending on how you tweak the cards but I say this....
I do FAH/WCG and same thing applies there.. So you'd not buy a card from a folder/cruncher?? Well just with my testing and such, mining is less hard on the card compared to folding/crunching and even gaming because of the peaks of power that the card/s have to go through. The mining cards sit at a constant state regardless..
I look after my cards, I support crazy plans and I've found that first hand, thermal pads/shims can make a massive difference to the temps... Example being one of the 3080s we used. Memory temps with stock pads, through the roof, about 100C say for argument. OK so we change the pads, drops to maybe 90C. Mate tried shims not to long ago and oh my word it was like night and day. RAM temps now around the 60C's for the same setup/settings and the like. If that's not impressive, I don't know what is... Cheaping out on how to make the card just makes a good product crap in my eyes and I don't agree with it. But business being business, gotta save them pennies....
So leaving it as a stock card and gaming temps through the roof, but putting something better in it, temps cold in comparison... Hell my RX480 have been mined on for a good year or more over 5 years now, never an issue. Look after your kit, the kit just lasts and works
Mine seems to be!!