They are a bit hard to calculate with. I know my hash rate will be 2184 for LC Difficulty I kept as standard import no clue what Pool Fee is.
The mining pools charge a fee to run the servers and take some of the risk. It's usually 2%.
At that point I will be making $420 a month with a elec bill of $75 so 320 a month Seems quite good. That is with 3 x 7970's with 5k should I get 2 rigs both with 3 x 7970's. So many things to think about.