Quote from: vpcrypto2018 on February 22, 2018, 11:46:42 PM

Hi, I have the opportunity to buy a mining rig with 4GB RX 570 and 580 cards at a decent price. That will work just fine for ETH for now but how about 1 year out? Is this a good investmen or should I better pay more and get the 8GB versions?

4 or 8 Gb is important only for the Ethash algorithm. There are other algorithms.
The question was rather in return on investment. Conditionally, the first year pays off the second year net profit. The size of the DAG will be enough for two years for the 4Gb. https://investoon.com/tools/dag_size
But no one knows what will really happen or what next generation of cards will be released tomorrow. This can greatly change the balance of power.