My Latitude I bought used on Ebay too, for some ridiculously low price. I bought it around the time I5s were coming off a 2 year lease, so there was a glut of them. It has been very reliable, probably because I never move it. By then, manufacturers were getting good at building laptops that could take some physical abuse. It came in perfect condition, so I expect the original user never used it as a portable either.
I tend to replace computers when they break, so this one may last a while. It's still way faster than I need. Plays video just fine. I could probably use some better speakers, but the audio hardware is way more sophisticated than I need.