eBay is too high barrier for me. For Amazon- the fact that shipping is fast and cheap/free and returns are easy outweighs any other seller for me.

My ebay thought process, which makes searching a chore..

- Returns will probably be a hassle so I really better want it. - Is it buy it now or do I have to bid? - Exorbitant shipping price or it's "freight" with no price - Shipping may require signature and I have to be at home - Checking seller reputation - Checking seller location