Seems a few of these Antminer E3 are showing up on eBay already. There are even many people bidding on them.

One of them is at $188 USD currently and claims to be able to mine "ETH/ETC" which seems like false advertising since they can't mine ETC anymore. The seller stated also "No returns or exchanges"

Another is at $1500 USD and claims to be new in the box. Anyone remember the retail price for these? Wasn't it like $800 USD when they were new? Pretty sure it will never sell.

Last one is at $278 USD and will probably go even higher as there are still over 1.5 days of auction left.

So assuming 30 days of mining left for ETH, it would make a profit of $100 assuming free electricity. With 10 cent power profit would be able half of that, $50.

The problem with eBay is that its more than likely that the buyers will just make a claim and send it back when they find out that it won't mine ETH anymore. This similar situation happened back in 2016 with the BTC halving.