I HATE selling on FB marketplace. My experience has generally been worse there than craigslist when it comes to people messaging and then ghosting me after I respond, people mad that they can't afford it, etc. Most recent example is I put my 2 year old Chinese JW Speaker ripoff headlights up a couple weeks ago for $50. At the time I bought them, they were $115, I think now they might be $90 on Amazon. Some dude decides to make a personal crusade to hammer me for my price. Claiming that's what they cost new and then giving an example of some other cheap chinese lights that are generally regarded as garbage. Never would let up, so I blocked him. Sold them the next afternoon for asking price to a guy that drove 30 miles for them, and only needed one 'cause he was buying for his motorcycle. 6 people were behind him in line if he didn't come through. Seems like my pricing was pretty reasonable.
Worst craigslist experience I recall was selling a rug that my ex wife picked out and new wife didn't like. If you've bought rugs, you know they're one of those things that cost more than they should. I think this one was in the $250 neighborhood new. I put it on CL for $100 I think. It was in like new condition being that it was in a dining room of a 20-something couple that had no use for a dining room. Guy wants me to take $80. Ok, whatever. Then he wants me to deliver it 30 miles away; don't think so. I offer to meet him at a convenient location 10 miles from me that was close to a dinner spot I was craving, which he accepts. Then asks if it'll fit in a Mustang. I re-state the shortest dimension of the rug which was clearly listed in the ad and told him he'll have to measure. After all that, we meet up, he pays me and loads the rolled up rug into his convertible Mustang running over the center console and sticking out over the trunk, and then informs me that I was the most difficult person he's ever dealt with buying something on craigslist.