Hopefully AMD doesn't get too crazy with their pricing, but even from the TechPowerUp article, it states:
Even MSI CEO Chiang's statement couldn't prepare us for the prices we're seeing for the ASUS motherboard lineup. The cheapest AMD X570 motherboard from ASUS is the Prime X570-P, which is priced at USD $159.99. Its slightly bolstered twin, the TUF Gaming X570-Plus will go for $169.99. A variant of this exact board with integrated Wi-Fi 6 will be priced at $184.99.
As long as the average builder can get a good board for $150 - $200, I think it's reasonable for what it brings. Of course prices will be higher at launch (just like Intel), but within 6 months, I bet there will be some "low-end" X570 boards in the $120 - $130 range. Then whenever AMD decides to launch the B550 chipset, there will be even lower priced options for those looking for them.
It all just depends on what the legit reviewers tell us on July 7th. If AMD's next CPUs are as good as they are hinting they will be, I think the value will be there regardless of the motherboards being pricier than what AMD boards have typically gone for the last 15 years compared to Intel's offerings.
However, if the CPUs don't live up to the hype, there's going to be a lot of unsold enthusiast level boards getting BIG price reductions. That said, the motherboard manufacturers must be sold on the CPU's performance or they would not being making so many top-of-the-line models.