If your electricity is expensive, you can use 1070 in a very efficient way, at almost 4.00 sol/w, at about 70 tdp of FE (or 100 w ) the card produces 400 sol.
So it’s 450 sol/s at 160 W, or 400 sol/s at 100 W.
The 1080ti can realistically give you ~ 780 sol/s at ~ 290 W.
So based on these numbers, you can pick what you see fit for you.