If we're gonna talk old machines though... Oi. I think everyone remembers the Commodore 64. A nice little machine and a sort of benchmark in home PCs for plenty of people. But before I had that, I was using a Zenith Heathkit. A built it at home, including soldering, job. It had 32k internal memory. 3 5.25" floppy drives. One drive was your OS disc. One was your currently running program. And the third was your storage location. I learned COBOL on it.
The first company I worked for, doing system upgrades, bid a job to replace a Catholic school's computers. They went from a bunch of XT/AT machines on an IBM server with a token ring network. The job was to upgrade them to 386 DX2's. A nice little job, the company massively under bid the project, because they had a buyer lined up for chips out of the XT/AT's. Turns out you can't buy those chips brand new at the time, they weren't manufactured any more. But they were in use in some large heavy duty mainframe machines. To keep those mainframes up and running they needed chips. The company I was working for was reselling the chips out of the XT/AT's for a good profit.

Made a fair bit off of reselling the copper and metal frames too.