Having learned that a solution may lie in purchasing an older Lenovo business computer model, I'm posting here to find out what the sites are for buying used and refurbished business computers whether Lenovo or other brand. The logic is that the displays on older business computers may omit the features in modern computers that cause the headaches, fatigue, and nausea that I experience with most of the modern computing devices that I use.
I tried the Lenovo site, but don't see any older, used computers for sale there. Which sites have users here tried to purchased used laptops? Ebay? Facebook Marketplace? Please inform.

I normally use ebay, its low risk for actually getting what you buy and it working out of the box, but ebay won't enforce any kind of warranty offered.

I've just been researching this and so have found more options to ask about. Any thoughts on Tekrefurbs; or Refurbtek? (yes, they really are two different entities).
I mention these two platforms because they have a substantial selection and 30-day return policies. Any feedback on these two services would be helpful.

dev