I know 2.8 is far from finished and we don’t know how demanding EEVEE will be when it’s done. Anyway, the HD7770 has similar performance to a GDDR5 GT1030 or GTX750Ti when overclocked, but costs roughly $40 used from China.
I would be pairing it with a machine that has:
8GB of DDR3
Currently, a heavily overclocked GT610
I’m on a super tight budget, but I’ve almost saved up enough to buy a HD7770. Should I go ahead and make the purchase, or shoot for a card like the GTX1050 or GTX1050Ti?
Edit: doh, re-read the post. So you are looking at the used market. I would look into getting something like the above mentioned 7970 Ghz Edition, mostly because of the 3GB VRAM. I’d look at performance second, memory first.