Hahahaha, my X240 (which still runs and even has a few upgrades) is valued at $0 because there is a crack in the chassis at the fingerprint reader. Without it would still only be ~$35 - I'd spend more just getting and replacing the keyboard cover than its worth.
Neat program! We do a lot of Trade-Ins with our old cell phones and usually do pretty good with the vendor's trade-in offers. That said, my T530 Thinkpad laptop was valued at $7.55 for this trade-in. Still runs like a champ. I think I'll just keep using it ;)