With the current price and difficulty you are expected to find 1 block of nexus with 400MHASH on one day. (2 1080ti cards)
1block=$25
So the profit is around $12.5 per 1080ti card per day. (nexus sp-mod 0.05btc donation)
Yeap, but your forgot to mention, that you need 1 core for every card you have and that even Nexus developers don't know how to calculate expected time to find 1 block. And that means, that you can find no block in a day even with 8 1080ti rig. (as it happened already to many who tried get that 12.5$ per day bullshit)