What I see more of on Craigslist are people with delusional seller's syndrome. Too many sellers think the depreciation value on their stuff is about a dollar a year. I've seen many people asking for MORE money than what they paid for MBPs. Just because you throw a larger HD and some RAM in a 2008 MBP, that doesn't make it worth the same as a 2011 model.
Electronics are like cars. They depreciate considerably every year because new ones come out every year.
As was said earlier, "Things don't have an inherent value; they are only worth what someone offers to pay for them."
I personally believe in the golden rule: He who has the gold, makes the rules.
People (buyers) are on Craigslist to find a deal, otherwise they could just buy a refurb. If you are not a retailer, there is no reason for anyone buying something to trust you and take you at your word about condition, use, etc. A deal is NOT a few bucks off MSRP minus tax. If you get lucky and get that for it, congrats. Maybe its supply and demand in your area? Ipads are luxury items and they are not rare. $350 is not lowballing. $50 is lowballing. If you think its worth so much, hold onto it until you find a buyer but the longer you keep it the less its worth. It seems to me like every seller is looking for a sucker; an uninformed buyer willing to pay almost what you paid for it when you bought it. I know from being an experienced buyer that if you offer a fair price for something, sooner or later someone will take it. Its just a matter of who has the most patience.