You bought it from a dealership. They probably had it as old stock and wanted to get rid of it. I'm surprised to see that they have not had more stuff up on ebay. Being a new seller doesn't make it less expensive. They just got rid of it and you were at the right plae at the right time. Let us know how it fits and sounds.
Thats actually not true. With so much fraud and scam activity going on with ebay and other online purchase sites, people are getting smarter and (unfortunately for the legitimate sellers) staying away from items they feel might be illegitimate. I see it alot with Rolex watches and other high end expensive items. If you can find a new seller who you can somehow verify is legit, you can get a substantially better deal than someone with excellent feedback who people trust right away.
You are taking a calculated risk whenever you do purchase from someone who is a new unverified seller, and to some people its just not worth it. Much like those who purchase Certified Pre-owned vehicles for thousands of dollars more than what a wholesaler or corner lot would sell the same car for.
If a new seller makes the mistake of starting something with a ridiculously low starting bid, the lack of commitment from the typical buyers will leave the price pretty low. Obviously if they put a reserve on it, or start the bid at market price, then yes it doesnt cost any different.