Our Helpdesk does full on replacement work. I have seen them swap out mobos even CPUs. We are our own service contractor with Dell, HP, and Apple.

Wow. I want to work at that helpdesk. Every helpdesk I've encountered is just an intermediary for outside service.

Well, with the cost of finding a specialist amortized over 59 computers, surely it becomes worth it at that point.

Corporations and big organizations don't think like regular people. Yes you can repair the computers saving money, but now there would be no support from the OEM, and they would have at least two different systems - the repaired ones and the working ones, because I don't think that motherboards for custom office PCs they have (like HP or DELL PCs) are off the shelf. I have an old compaq PC I upcycled as a home server, everything inside is built to fit together and be very reliable, it is nowhere close a typical PC build. The motherboard isn't even square.

Don't OEMs offer paid repairs themselves?