I rescue commercial laser printers that are being disposed of by companies, service and refurbish them and resell them. Partly for money, partly to keep them out of landfill.

This makes me and your dad arch-rivals 😬

I once got an A4/A3 colour laser multifunction, which normally retails for $12k, for $80. All that was wrong with it was a faulty door sensor. I just cut the wires and joined them together permanently. Used it for 3 years then sold it for $500. Never even needed to replace the toners

That's not necessarily true. Generally the cartridges shipped with the printers aren't filled entirely, or are otherwise smaller than separately bought ones.