I have collected a lot of stuff in the past and now I want to sell some. So far I had great success with Delcampe.net, it's a good site to sell your stuff, especially postal Stamps. It's specially made for collectors. Any other websites you know?
I have used eBay before, but never had much success there because of the fees. Once I did sell something I think I made like a buck or two off of the final price. The rest of the money was all in fees. Ecrater.com is another site which has worked for me in the past, it does not have any fees. However, you are responsible for all the advertising on the site for your products. A new site I have seen advertised on Facebook lately is called yardsellr.com. This site I have never used, but have seen success stories posted from users on Facebook before. Hope this helps out!
I think you need to sell different products on different websites. Mean to say you have a collection of different kind of products - right. So you need to search for different website for an individual product.
There is a good website for art collectors and designers called Etsy. Another good websites is Olx. A casual google search will yield quite some good leads. Most collectors sites are not scammy.