It's probably a snapshot. The OnBoard WiFi part is also worth exactly what it costs. I recommend an Asus PCE-AC88 or similar as a WiFi solution. As far as I know, the X570 with WiFi has one PCI-E 1x slot less than the "normal" variant.

Due to many factors, prices change constantly. Thus, there can be such a constellation that a mainboard that can do more is cheaper or equally expensive.