I'm uncertain of why $40 vs $300 is even a point of debate on HN. The latter is a one-time investment and you likely can expand it a bit i.e. add a 2.5" or M.2 drive later.
What's the gain of running 12 RPi, exactly? Do you do research work requiring distributed low-cost computing?
They are if the GPU can be attached. I avoid virtual machines in favor of container workloads from containerd for this reason. It’s easier to attach Mali GPU and do my work than it is to find cash in this economy for a dozen RTX’s.
What's the gain of running 12 RPi, exactly? Do you do research work requiring distributed low-cost computing?