Was looking to upgrade my Open Mesh gear (given EOL) and stumbled across this. Other places have the 5-pack in the $900 to $1100 range and this is even cheaper than the 5 pack of AP5-lites. Maybe in response to the AP6-Pro availability improving.
I know that they are not Wifi6 however given most people (including myself) probably won't have any Wifi6 devices for a few years yet I think that this is a good investment. Anything that I need gigabit speeds for is hardwired.
Love Unifi gear but I wouldn't say $640 for 802.11AC is a 'good investment' with AX becoming increasing common and AY around the corner.