Even if it is not an auction site you could run into infringement issues. Why? One the term is not a word. Two, the famousness of the mark. The more well known a mark is the more protection it has. eBay won a case for infringement against PerfumeBay because it contained eBay in the URL. There was a little more to it, the perfume sales started on eBay originally but it was a stand alone non-auction site when PerfumeBay went up.
I wouldn't take the risk, they are very strict about that. I wouldn't invest time and money in a domain name and a website and then having it taken from you because of trademark issue's.
lol checkout ebay.com.pk its parked on sedo i thing someone bought it to derive traffic , lol and ebay hasnt done anything yet.. so i suppose you can buy a domain with ebay in it, and use it as long as ebay doesnt notice it.
Ya u can buy it,i have already seen people using all those big site domain trademark in their own domains.