When Mr Hestia wanted to offload some of his stuff, he found a local memorabilia/toy fair, took a cheap table and sold most of it in a couple of hours. If you don't want to take it yourself, you might find someone who'll be happy to do it for you. Some people enjoy that kind of thing (like Mr Hestia, but I just prefer the quiet day when he's out). You'd need to do your pricing beforehand, though, to safeguard the good items.
The other thing he does is find a relevant forum or club and advertise it on their website. That way you are reaching people directly.
Ebay is a bit of a headache, increasingly so these days, what with charging for breathing while on-line among other things.