My offer is 400 max which is the ebay price for a 1080 FE now I just checked. Many bids are lower then that so I excluded those numbers. I also excluded all new prices from my price estimation.
I am willing to look at a GTX 980 or 980 ti for less then 399 and a 1080 for 400 or less. I know its a hard bargain but its all I can afford and quite frankly I cant get my hand on an rx 580s dude to fucking cryptominers..
WIlling to consider hybrid water cooled cards for a bit more then 400 lol
Estimated purchase time (sometime in the next 2 to 4 weeks)
Conditions: Must not have been used heavily for cryptomining or have had its stability destroyed by compute tasks as it will be used for gaming
I suggest not focus on a specific model, since I don't live in the US, I have to focus on what's available in my country and isn't overpriced. My tactics might help you in this insane times.
I usually sort the available products by price and browse from cheapest to most expensive (start at a decent price, like +$250 for high end graphics cards, otherwise you'll see a lot of crap).
Of course, don't buy the cheapest one you find, sometimes a much better one comes just for 10 more dollars.
Edit: specifically answering your question, a 980 performs similar (usually worse) than a 1070 but has half the ram, I predict it's not going to age very gracefully for power users. I wouldn't suggest getting it.