mate, I'm sorry, but where do you live?! the prices you've posted seems pretty high, I'm not sure that it is wise decision to buy cards on such high prices..
believe me, the prices well be cheaper very soon, it is happening already.. so for example gf 1080ti normal price in us about 800$, not like $1100 which is really high.. and same with gf gtx 1070, good price for it about $420-450
I just checked with another seller and yes the 1080ti OC I can get for $813
And rx580 8gb OC at $398 and used ones for $300
Btw I live in india