Beating eBay? No way. Even if you have better script, support, etc you won't beat eBay. You'd need like $ 20K in SEO to beat them.
The point and or the concept is not to beat Ebay but have a decentralized system which is not monitored and controlled.Ebay has private owners/customer support/ and an entire set of selling rules .OpenBaazar doesn't have any,you can pretty much sale your pubic hair or a fetus ,your trade won't be monitored.In the long run,there will be trade policies I guess.