Right now, I have 5x rx580 and I make 0.7ETH per month. Because I dual-mine with Decred, I also make 2 DCR every month at the cost of more electricity. Because yours is cheap, try to dual-mine ETH with decred using claymore's dual-miner.
As an alternative, you can try to mine other coins. For example, at the time of this post, ethereum classic or monero can give you a better profit than ethereum.

Check https://whattomine.com/