Flagship Vega using current market conditions will go for well over $500. Possibly even $600. This is if it isn't as fast as 1080 (which we all mostly accept it is). Shareholders would not appreciate a product being sold at such low costs if it beats the current performance encumbent. For AMD to survive as a business it can't offer a Titan X leveling card for a 'consumer friendly' price. They didn't do it with Radeon Pro Duo, Nano, Fury X or 7970. If you look at their aspirations, they will aim high on pricing but not more than Nvidia.
I can easily see it matching 1080 price if it performs better than it. Which of course makes it the better card. But, it's not even out yet, might not appear till May/June and that means Nvidia can comfortably drop prices on a year old card. And as AMD release Vega in 1st Half this year, Nvidia might be able to release their Samsung Pascal refresh (if that process allows it?). Or, worse, the longer AMD takes to release Vega, when they do, Nvidia start dropping crumbs about Volta and how it is super dooper awesome.
What AMD are trying to do this year is fantastic and I understand why they are being so patient but the longer they wait to release makes it closer to their competitions next generational releases.
And please note, I would dearly love an AMD Ryzen chip with i76950 performance and a 1080 beating Vega in my next build.