Are you looking for a used/2nd hand Antminer that could mine ETH? Bitmain doesn't release yet any miner that could mine ETH so you can't buy any 2nd hand ETH miner.
They have planning to release a new one this year but I don't think that you can buy it for $4000 I believe the price will be higher than that.
I don't mind mining BTC. Is it safe to buy used ones?
i saw a few used Bitmain for like $2000. I'm seeing these Bitmain hashing 1500 Gh/s. Is it really 1500 Gh/s for $2000?
I spent a lot of money on GPU rig and it’s hashing 1 GH/s. Sound too good to be true