I have sold a ton of stuff on Craigslist as I've redecorated since moving a few years ago, and have generally had great luck - I've sold a few pieces of furniture for only slightly less than I paid for them! I make my ads VERY detailed - am honest about the condition of the items, take high quality photos, provide accurate dimensions, etc. I usually list items on a Thurs. and try to get people to pick up over the weekend. I have had the occasional buyer no-show but have find that I can tell pretty quickly if someone is serious or not. The first person who commits to purchasing gets dibs, but I don't take the ad down and if they no show I will contact the next person in line, if there is one. I am selling to get these things out of my house, not because I'm desperate for money, so if I get a snotty response that's something like "your price is too high, but I will give you $100 [of the $200 asking price]", I just click delete.
The only real problem I ever had wasn't even with an expensive item, it was a woman who was buying a rug I had listed for sale for $60 - I had specifically noted in the ad that it was a custom size, 6'x6', rather than a standard 5'x7'. I should have known from the get go that she was going to be annoying...her emails were snippy and she kept asking for more photos (which I sent), and then she said she would take it and asked me to hold it for her since she was coming from about an hour away and really, really wanted it. I agreed, but she then kept calling and pushing back the pickup time. Basically, I'd sat around at home for the whole day waiting once she finally showed up. She finally pulls up in her Lexus with her teenage daughter and a friend. Looks at the rug and says real snotty "ohhhh...it's so much smaller than I thought it would be, it's not going to work for my space." I'm sorry, but if you're driving two hours RT for a RUG do you not, you know, MEASURE your space before you leave the house? I told her, in response, that it was 6x6, just as listed in the ad. She says, "well it doesn't LOOK that big." I offer her a measuring tape...but she hems and haws and finally says, "well, since I had to come all this way, I guess I could give you $20 for it." As if she was doing me a favor. Her daughter and her friend looked mortified. I said no, and I was not very polite about it either - told her that she should have the common decency to measure her space before the next time she makes someone sit around waiting for her all day. I ended up donating the rug to charity, I was so annoyed.