Those are 4gb.
Even if they were 8gb; you can't use old prices to justify your reasoning.
A 4GB has no difference on hashrate.
It will soon not be able to mine Ethash; and its resale value is significantly less.
4gb 17/DEC/2020
eth will move to progpow which will already turn it useless x nvidia. AMD cards will move to other coins example, monero which at moment gives the same value as mining eth and memory wise will never die off as monero can be mined with less than 1gb memory.
4gb GPUs have less resale value than 8gb.
Yes progpow will make AMD useless for ETH as well.
Which is why I told you earier:
If you really only want to mine XMR; sure get an AMD GPU.