Technology

They oftentimes pop up on eBay (and sometimes Newgg) for fairly cheap. I've seen many older systems like that pop up for a couple hundred bucks with pretty good specs, even by today's standards.

Look for surplus sales, many large orgs (esp. universities) have them periodically throughout the year. I got a PC for $50 years ago, and it worked, it just wasn't modern.

I recommend at least upgrading the PSU though, since the ones that have tend to suck, and consider getting a new case as well since a standard PSU may not fit and they're certainly not big enough to hold a GPU.

Used corporate laptops are readily available from numerous channels. Most buy the 3-year warranty with a planned replacement at 4 years, and there's roughly 1 cycle per year (which lines up with a new model released each year). These get sold to refurbishers and resold from there.

IOW, figure out which Dell Latitude, HP Elitebook, and Lenovo Thinkpad models were released about 5 years ago. Then head over to eBay, Amazon, Micro Center, Newegg, etc and search for that model. Be very careful on specs - many remove and destroy the SSD for data security, and that often includes the mounting bracket. There may be a wide range of options, from a 1366x768 screen to 4k, or SATA vs NVMe, etc.

It looks like you can probably get a Lenovo T470 for about $150 or so; even less if you're willing to deal with your own hardware repairs/upgrades.

maybe we can get those on the cheap and install linux on them?

They're pretty much never thrown out when decommissioned, they're mostly sold to refurbishing companies that clean them and sell them to consumers or developing countries. So it should be pretty easy to get your hands on them actually. I recently bought a thinkpad T470 for $200 with decent i5 CPU, 16gb ram and 256gb NVME.