there exist numberless subvariations from many laptop models - so it's likely to end up with error messages that might be fixable or not.

Used laptops are often overpriced compared to new lower-end models that have better specs.

On the other hand, I couldn't resist when I was offered a middle-aged Asus for only 40,-, without HDD and with hinges broken out of the lid. The latter was fixable, and I had a fun day putting in a new SSD and setting it up the way I thought a computer should be set up ;-). Im writing now on this "well broken in" machine ;-)

So it all depends on what a person prefers...