Even if your power cost is 6 cents, it's probably a good idea not to own any Radeon RX 5000 or older / GeForce GTX 1000 or older video cards. I would wait until the big PoS crash and buy RTX 2080 Ti's or RTX 2070 super or RTX 3060 Ti cards for cheap, as they are very good at non-ETH algos.