@mcc I’m not sure where you’re located in realspace, but I know lots of places have a local nonprofit that does electronics recycling and refurbishment, and they will often sell old used laptops that have Linux installed and configured on them.
If you don’t have one, my local (FreeGeek, in Portland, OR, USA) happens to have an eBay shop where they sell some of their stock: https://www.ebay.com/str/freegeekportland/Computers-Tablets-Networking/_i.html?_sacat=58058