I have been mining BTX (bitecore) with a single 1080 GPU with a average of $2.50-3/day of payout and about $0.80/ day of power usage. I already had the card for gamaing and simply have it mine when I'm not using the computer. I won't retire on that, but for nearly 0 effort, I net about $500/yr in straight return, and then since I am holding, there is the growth factor should it happen as I expect.