I guess the answer would be relative- how much $$ are you talking about? The obvious concern would be UV degradation of the plastic, depending on how much time it spent outside. If it was stored outside, I would think that the plastic has grown quite brittle in the last 18 or so years. Regardless, I doubt that the boat is worth more than $150, even in great condition. The exception would be in the weeks before the Gore race- you could probably sell one for $200 in the parking lot there. Most are probably worth about $75 to $100. You might have some difficulty finding a non-keyhole skirt, too.
The crazy part is, old boats seem to have a way of being bought for more money than they're worth on eBay; typically by a guy in Kansas that wants one for his lake and is unaware of the value. Lots of overpriced boats out there.
If you're looking for a durable downriver design, there are probably better options for slightly more money. Prijon has made a variety of WW / rec hybrid designs that would be better options for the money. Go to www.playak.com/kayaks
and look at the 'Allrounders' and maybe some of the rec boats. Also- There's evidently a dealer in Texas that has a storeroom filled him old downriver-type boats (Pirouettes & such) that are brand new. IM mike pagel and ask him the name of the shop.