And the terrible user experience of having a stranger say "I know we agreed on $200, but now that we've half way loaded it into my car I think $150 would be more fair."
Craigslist over the past 2 years has had zero issues, I've interacted with fairly even keel 40+ year old people that are easy to work with. The "no lowballers, I know what I got" crowd has mostly departed Craigslist.