budget blue iris reference system

I still find a 60 USD 2MP starlight cam expensive, given than for 120 USD I could get a 6 analog cam + DVR from same brand (Dahua). If you were poor would you settle for a DVR+ Analog? I'm not poor, but trying to be cost effective.

Saw a bunch of these pop on eBay recently.. looks like they can hold 2 x 3.5” drives - can anyone confirm that two 3.5”s fit without using ductus-tapus? Also looking like there’s nvme support as well? Any caveats from experienced people here on this type of system? HP Z240 SFF...