Because many people are stupid!!
eccb06.org was the website for the 5th European Conference on Computational Biology (ECCB '06)
The eccb abandoned the eccb06.org domain and is instead using the eccb2006.org
I didn't check what the stats actually are, but the domain has a lot of backlinks to it. Because of the topic, there is probably an abundance coming from lots of .org and .edu sites. Because of this it probably has a fairly high PR.
The bidders are probably looking at what I'm assuming must be a high number of backlinks and a high pr, and bidding on it based on those stats.
It seems to me that the only value of this site is in the PR. If you use build a page on the domain and use it as a link silo to your money site then maybe you can get some link juice from it.
If you wanted to actually build a money site out of it I think you'ld have a project ahead of you. All those backlinks will be keeping it ranked for biology conference keywords. Once they start making additional backlinks and do some onsite seo they could get it to rank well for there targetted keywords as well. But why? The original niche isn't going to be of much use. The name is stupid for anything other than something that can use the same acronym.
Like I said its possible that you could use it as a really good link silo, but I wouldn't pay that kind of price for it myself.
edit- I just looked at the auction and it shows a PR6 with only 1 inbound link. In reality it has a lot more backlinks, because I found more than that by just searching for it in google. But it doesn't matter, the site has a PR6 and I'll bet that's all the bidders are looking at. Whats funny is that if that PR6 is coming from just a single backlink then the buyer better hope that whoever runs the linking site doesn't realize the error and change the backlink from eccb06.org to eccb2006.org or even remove it completely. If they lose that single backlink then that pr isn't going to last very long. LOL