Two initial comments for you;
You've picked a really tight market to try and crack, and while it is your passion you may find it really hard to compete without any volume purchasing, even then it can be tight in that market.
As for buyers on ebay wanting the best deal, someone needs to show me a site where consumers don't want the best deal!
There is two major reasons that drive online purchasing, convenience and price!
If you are going to sell online, those are the two biggest hurdles you need to over come wherever you list, not to be successful, but just to survive!