Not sure, but I seem to recall that BW did some sort of major (minor?) limb change within the last 5 years or so.
Worth? I think they are awfully expensive but I know for a fact that they are very good bows and I certainly can't say anything bad about their performance, quality or service. It's just WOW, that's a lot of money for a bow... Especially when they mostly all look exactly alike. I was really glad to see them start offering something besides the laminated woods. Of course I'm a po'boy. If money was no object, I'd probably have a couple of them hanging on the wall.
Just a wild guess, for a '98 in good condition in a hunting weight....I suspect the seller would want between 500 and 700 but I wouldn't be suprised if they wanted a tad more. After all, a new one is probably over a grand by a good bit. Last I looked they were around 1100 and that was a couple years ago.
A fair indicator of current value is one of the online auction places that I'm sure you know about but often that is somewhat false too due to collectors driving up prices on certain bows. Bears and Widows being two of the most common. Also, the start of archery season usually sees an uptic in prices too. Best time to buy is usually about February to May in my opinion.