The 1080s are much cheaper than that, around $600 to $700. The 1070s perform well too, and their price is around $450 (US dollars, these prices).
Probably something like $8,000 and up for the 2697 based systems in the top place, the processors alone are close to $3,000 or so each and those systems have 2 processors in them. Cores are as follows - a single Xeon 2697 (the second place ones on the benchmark)has 18 cores, the top systems on the benchmark have two of those processors in them (as Xeons can work together like that) which makes 36 physical cores, and each core can run two threads, making 72 logical cores (apologies if my terminology is a bit off!)
Hope this helps!