That item has no reserve, not sure why you think it ought to. It's a straight auction with a buy-it-now option.
buy it now just gives people the option of buying it outright rather than waiting to see how high it goes, most experienced Ebay sellers do not use this combo, but you do see it quite often on automotive parts because people tend to just want to buy them outright.
Its called "Longer lasting Buy it now" I know a genius name! haha I guess ebay is testing new stuff out they say it will make an item go for more money in the end. Only in certain categories though not sure which ones exactly.. Feebay Always out for the buck!
Sorry after reading what i just wrote it kinda may not make sense. As Dave is saying that its an auction with a BIN option he is correct. Usually though the BIN drops immediately after you bid on the item(makes no sense to start and item at .99 with a BIN @ $100) Unless of course you get the immediate sale for $100 which rarely happens.
In my experience the best BIN situation is 10%-15% over what you start the item at which actually entices the buyer to BIN without waiting and saving a few bucks.
So with all said and done thats where the "Longer lasting BIN" takes over. The BIN may drop when the bidding gets higher or it may be up there until the end. Ebay is getting weird...