Well at $600 for a RX 580 it may take you a year of 24/7 mining to even get your money back. If you ever want to sell the card to upgrade in the future, you will take a huge loss. If I were that desperate to start mining, I would rather buy 6-7 used HD 7850 2GB on eBay for ~$500-600. That will give you 108-125 MH/s on Ethash coins with a Dag <2GB like UBQ, EXP, PIRL, etc and also ~1170-1365 H/s Equihash and ~3000-3500 H/s on Cryptonight. Much better ROI and you can also trade those coins for ETH if you want.