Really nice looking fretless on ebay
 
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=140244364704
 
Anybody have a history on this?
 
Looks like the serial number ends in 5435. I've requested the complete serial number.

I found this posting from April 2007 with serial number 89C5435 - 5 string fretless.
 
Hope it helps.

Wow, I was considering buying the bass from the owner last time it was for sale, about a year ago.  It's going for way more than what I almost bought it at: 3,500 USD.

I know for a fact that the seller bought that bass for $3500 or less, so it's a pretty significant markup.  
 
Having played the bass, I would pay $3500 for it in a heartbeat-it's an incredible-sounding and playing instrument. My only complaint with it was that it weighed a ton-it's easily a couple of pounds heavier than my Series I, which is no lightweight at 12 pounds.
 
I've talked to the current seller and he seems like a trustworthy dealer, but all of his instruments are overpriced by a pretty fair margin considering market value.

I also spoke to the seller, about six months ago, and got the same impression. I was told that the price is firm.

I thought that looked familiar; thanks Art!