Has happened to me literally 30 times. I'm talking about CL not INGO.
I have had my fair share of decent "wheelings and dealings" (as my mother used to call them) on craigslist, but not without a fair amount of stress on getting jerked every which way but loose when I'm selling something. The absolute worst was listing an old BMW K100LT I sold on there, my inbox was just overflowing with offers, all about $1000 short of my asking price. I had about $500 "wiggle room" in what I was willing to take from my listing price over my absolute bottom dollar price. I even told one guy that I'd light the MF'er on fire and watch it burn before I'd take his offer. And so is business, I've been around car dealerships for the last six years of my life, you get used to getting lowballed by people. It sucks, but that's just how people are accustomed to doing business anymore.