I too have had less than stellar experiences on both eBay and Craigslist. The last time I tried selling on Craigslist I listed a brand new lamp, unopened in box. I included all the manufacturer's pictures and details (dimensions, weight, ect...). I received an email the next day from a lady interesting in purchasing it. She asked if we could make the exchange in a Walmart parking lot (in retrospect, that should have a warning sign). 5 minutes after the agreed upon meeting time I received a text that she was running late but would be there any minute. 15 minutes later she arrived and instead of apologizing for wasting my time by running late she insisted on opening the box before purchasing it. I refused since I was worried this would lower the value if she chose not to purchase it. She was being stubborn though so I eventually acquiesced. At this point I really just wanted to offload the lamp and go home. Upon inspection she said that she was sorry but wouldn't be buying it because it was smaller than she thought it would be, never mind the fact that I included the dimensions in the listing. As I was about to drive away, she offered me half of the agreed upon price. Why she suddenly wanted it again despite it being too small I'll never know as I immediately sped away.

Like you, I have a lot of stuff I'd like to sell. What I want: a company to send me pre-labeled and pre-paid shipping containers that I then fill with my stuff and leave on my front porch (safe, rural neighborhood) to be picked up. Every week or so they pay me until everything is sold - minus a commission so that our interests are aligned to get as much as possible for each item. I can't seem to find a service that makes it that easy though.

Oh, and that lamp? Amusingly, I took the lamp back to Home Depot where I had bought it new 3 years earlier. I had no receipt and I told them honestly how long ago it was originally purchased. None the less they offered me a full store credit. The catch was that they no longer carried that brand of lamp and hadn't for over 2 years. In fact, it had been so long since they last sold the lamp that they didn't have pricing information on it in their database. Since they couldn't determine how much I paid, they instead gave me store credit equal to that of a lamp they currently had in stock that we agreed was comparable. I was so impressed by their generous return policy that I promised to one day spread the word of how awesome they are.