I find out that RTX 3070 and RTX3080 are the best gpu for mining right now but I can't find where to get used variants as the new ones are way too costly for me, anyone know where I can get this graphic card ( used versions ), I've tried ebay but find other low cards from RX470 to RTX2080s only, thank you
They are indeed too costly, it may take a year or two before you can see used versions of these graphic cards, why don't you consider lower cards? RX580 costs as little as 158$ online, getting 5 of this card won't cost you more than 700$ roughly and the Ethash speed already beat a single RTX3070, a RX580 can do 27mh/s and 5 RX580 will give you 135mh, that's way better than what RTX3070 would ever give, using RX580 will bring ROI in just few months