That is rumored pricing. Nothing official has been released, and probably won't be until release day.Oh because we always need a link to back our statements....
https://www.pcgamesn.com/amd/amd-zen-release-date-specs-prices-rumours
A slower octo-core you are going to overclock because you don't want to spend 500$ on the faster one but "think" a lower end board is going to handle the overclock.....
I dunno boys. Don't get super hyped on the efficiency and pricing deal. These are release pricing. Wait it out a good 6 months and those prices should come down.