Re: AIAW ‘98 Vintage, any better than the new ones?
Quality-wise it's going to be very similar to a current production AW. The chassis will be of a welded construction, rather than pressed-and-pinned, which effectively means you can't have the factory swap the rifle from fixed to folding, if that was your intent. It probably has a dovetailed receiver, so you're going to be limited to using an AI or similar European dovetail scope mount - this isn't a problem unless you intend to use a few certain niche scopes or scope accessories that can only be mounted onto a picatinny rail.
Depending on condition, accessories, round-count, it's probably worth between $4500 and $5000, IMO. MSRP on a new AW in that configuration would be just about $6k.