They could / should switch to a Pi Zero or Zero W then, save more than half on the expense of the devices.
Or make it so you can plug in any Pi, is there anything of a secondhand market for those yet? I can imagine there isn't though, those things are cheap enough to be throwaway / lose in a drawer devices.
Neither of them is really high-powered, believe me. :)
But using one with old B boards could be excruciatingly slow at times, which is why I just had to upgrade mine - itβs since become a lot more productive in the sense that my tests take around 5 minutes instead of a whole hour :)
I doubt you're the only one on here with the understanding that a bunch of Pi's is not really a supercomputer cluster, but thanks for the clarification smileyface.