I am actually pricing out a build, and yes, the Kaby Lake 7700 is $350. How much can AMD shave off the price for a processor that isn’t any better? While the processor is now the biggest single expense of most builds (except for gamers/designers who spend more on graphics cards), it is still less than a third of the cost of a whole new system. I don’t see myself casting my lot with a new AMD processor to save $75.
I think you might have missed part of the point - if AMD does come out with something close, but not quite there at - say - $200, Intel is going to have a hard time justifying a $150 premium, so they’ll likely have to drop their price to $225-$250. You’ll still get the Intel processor you prefer, but it’ll cost you 1/3rd less.