It's quite a normal reaction that that you would find these site's prices higher than eBay's.
I mean whose prices are actually lower than eBay's?
What I suggest for now is to try and contact the suppliers and have a deal for wholesale or dropship prices.
I can still provide a few searches for you for Lego and related products.
In terms of eBay products, I suggest you look into their eBay top picks, top rated sellers and Google does wonders for research.
You can also try our Market Research Tool - Link hidden: Login to view
Hope this helps.