I've developed a mining profitability calculator which forecasts the net hash rate and daily ether to miners and thus gives a more reliable profitability calculation. . Let's say you spend $2k on a rig that does 150 MH/s and 800 watts at the wall.
For example, say my mining hash rate is currently 250 MH/s and we use CryptoCompare's Ethereum Mining Profitability Calculator to project my gains: Awesome! I'm going to be making $900 a month, and better yet I'll be making $10,000+ dollars a year. Sadly, this is a naive