Services like Ebay and Amazon steal so much of your revenue in listing fees and selling fees that it can make it very difficult for your business to succeed. However there is a reason that they can charge you, and that is because of the marketing of users they have. Unless you have the traffic it can be difficult to get your products out there.

In your case of second hand collectiables - I would look at sites like WIX or Bandzoogle - that for a monthly set fee $20 you an use their templates to create your site. The massive bonus being that you can upload as many products for sale as you want and they wont even take a cent of your sales.

But this doesn't resolve your problem of traffic - there a number of strategies you could implement, the first I think would be using social media to connect with very targeted users. Directing your marketing to your target market is a key to success.