To translate, yes it will. The draw per day to run the machine over and above what it was already doing is around 28p per day or 8£ a month on the energy bill. At the end of the month for each RX480 I gain around $200 at current price if you take away the 8% it takes to get that back into my bank account i'm still quids in. You could at current difficulty and current ETH rates pay for another gfx card within a few months. however just a month and a half ago ETH were valued at less than $80 so as others have said its a risk but at worst its going to cost you around a tenner to find out

If you have no idea what you are doing you might find it takes you a few hours to get set up but its worth the investment of time to try.