From what we know, Nvidia is only going to initially announce the 1180 and maybe the 1170. Then they'll start shipping the founder's edition a month later.
2-3 months after that, they'll announce 1160.. another 1 month goes by and they start shipping founders edition, but who wants to buy that?
People interested in 1160 will have to then wait for another month till vendors like Zotac, MSI etc get quality approval by Nvidia to launch their aftermarket cards.
All this basically means is that people interested in buying 1160 will have to wait around ~6 months from the date Nvidia announces 1180 to get their hands on 1160.
Nvidia hasn't even announced yet if the new series will be numbered 11 series or 20 series or if it will be Turing or Volta. We don't even know in which month they will ANNOUNCE the new series! . This could turn out to be a seriously long wait especially for someone on very weak GPU/inbuilt GPU like me (2400G)
Also, with the state of the market in mind, I think it's not fair to compare it with May 2017 prices. The price right now is a positive trend especially compared to 1-2 months ago where it was difficult to find a 1060 6GB below 30K.