I'm glad I'm not the only one that thought the same thing about the Axzez Interceptor!
I was giving this some thought the other day and pulled up the following spec list:
| part | $ (USD) | link |
| axzez board | 120 | https://www.axzez.com/axzez-circuit-boards |
| 3d printed case (maybe someone can modify it for a 5 bay) | ? | https://www.reddit.com/r/homel…s_4_bays_and_itx_support/ |
| pico PSU | ~30 | https://www.axzez.com/forum/in…ed-questions#viewer-26j64 |
| cm4 | 75 |
total comes in under 300 probably.
pros of axzez setup:
- RTC battery
- 4 ethernet ports
cons:
- need to kernel patch unless you use their OS image (not mainlined? wat.)
- no sd card slot (booo)
The alternative I was looking at was the pibox 5 bay: https://pibox.io/order but that's "announcement late 2022"
pros of pibox:
- sd card slot
- PSU included
cons:
- not yet available 
For PSUs:
| product | $ |
| Mini-Box picoPSU-160-XT | 50 |
| RGEEK 24pin DC ATX 12V DC (Pico PSU) | 29 |
power brick for pico PSU: $20 (maybe just get a real psu at this point?)
looks like a bunch of BOM parts are here too: https://www.printables.com/mod…-storage-4-bay-35-itx-nas