You might also want to try gazelle.com. They specialize in offering cash for Apple hardware. I have had very good luck with them on several items. You can get an online quote by going to their site and typing in the specs. Their offer is then good for 30 days. They will even send you the packing material and shipping label. Very good service ....
I bought a 2010 Mac mini (sig) from CraigsList and I met the guy at a local coffee shop with my monitor and BT KB/Mouse. I tested it and made sure it worked. I think it's the responsibility of the buyer to do this. If the buyer doesn't, well, it's their own fault.
MRs is a little different. I trust people here more than Craigslist.
I sold two Minis this past year using Craigslist. I've found it's beginning to be like an episode of Pawn Stars. Everyone trying to negotiate. That and all of the scammers. Still, Craigslist has worked well for me selling used computers.