Smart people selling gpus now. Newbies buying it now. Then newbies will sell those cards later because it will paying pennies and not worth spending time. in this market is important entry time and exit time. it same like this you are carring bag and sell to another stupid 
and continues it then reverse it you buy same bag from stupid.It is same market like on the street you buy cheap on time you sell expensive on time. This rule of demand and supply.
and continues it then reverse it you buy same bag from stupid.It is same market like on the street you buy cheap on time you sell expensive on time. This rule of demand and supply.Yes true, i sell some of my old cards for good money at the moment. I can´t understand people who bought cards for the double price, this cards will ROI in 2 or 3 years maybe, if you calculating right
In September 2020 i get 13x P106-100 for 700€, now i can sell it for 2500€
Well last summer I bought a RTX-3070's sets @less than $500 each, and I was making $20/day on each for awhile on ETH, so I was definitely getting paid back, and all my gtx-1060, I bought for $100 new ( mostly galax +3 years ago, all still running like champs ) of course at 25MHS paid themselves off very well, at $5/day, only took 20 days to pay off.
Again the problem is that none of this stuff is available anymore
I still run rigs, but the payoff now is 1/2 what it was two months ago, so even though ETH price is down, obviously tons of people are now mining ETH. But's still worthwhile to get a few ETH every month, ... why not.