Just grab a 3-4 year old 13" business class laptop, like a Thinkpad X13. When they come off lease at 3-4 years, they hit the used market at pretty great prices. Some are in rough shape, but use trusted sellers who sell at reasonable volume, and their condition grading tends to be pretty reliable.
Be careful about upgradable RAM, or getting at least 16GB. It sounds like you’d be fine with 8GB for now, but 16GB will get you better life out of the machine.
You may want to replace the SSD straight away, depending on the write cycles. I’d probably just grab one with 256GB, and get a replacement straight away. Lenovo has all their hardware maintenance manuals online, to make checking compatibility and performing the upgrade pretty easy.