I was looking for some old code, I’d written (some old scanner code) and came across this: handout.pdf (610.0 KB)
“The first RepRap machines won’t be able to make quite all
of their parts – you will have to buy a few extra to add on,
like standard electronic chips. Our target is that all those
extra parts will cost no more than 500 EUR. So take those
parts, a couple of kilograms of plastic, and your time – and
you have a RepRap machine!”
“Our target date for the first fully- working RepRap machine
is 2008. The world will never be the same.”
I also came across a spreadsheet showing the parts for a Gen 1 version from Fab@Home (Fab@Home - Wikipedia) The cost: $2,210.16 & shipping.
Now you can get almost all the equivalent/better electronics/motors for ~50 & full machines for ~200.
I think this was the controller it used: LPC-H2148 Which seems pretty similar to some of the STM32s