Good lord, these prices will be ridiculous if accurate:
www.anandtech.com
ASUS Strix Z490 Mobos are around 200-230 € around here (looks similar in USD). In comparison Z590 ROG Strix
starts at $400, TUF at ~$300 (which has become the "value" brand), PRIME ATX versions are $250+.
And, no this isn't because of PCIe 4.0. B550 offers the same amout of lanes from CPU to SSD and GPU, yet it can be had for as low as 170€ here (and probably same for USD).
As you can also run Rocket Lake ini Z470, it really makes me wonder who is going to buy most of these MOBOs that offer very little more for most users, yet cost $100+ more?