Just to be clear: the 80-200 f/2.8 AF-D "two-ring" lens does date from 1997, but it is NOT the "first generation" of the lens...it is the third model in the Autofocus era...the earlier two versions had one ring, and had entirely different AF limiter mechanisms. I owned two of those early, one-ring versions, which weigh a full pound less than later models. As noted in this Ken Rockwell review, this lens was, at one time, Nikon's top professional-caliber 80-200 zoom lens...it's pretty hard to compare Nikon's top-level equipment from the late 1990's with anything Sigma has made..with Sigma, you never know when something will fail, fall apart, or collapse on itself...with a pro-grade Nikkor lens, you can expect a 30-year lifetime without a single incidence of service...
I honestly think it's quite fair to compare a 1997 Nikon lens design with a $800 Sigma. The Nikkor will have the right color rendering; the Sigma will have that Sigma yellowish cast to all its images. The Nikkor is made entirely of metal...the finish will still be on the barrel in another 20 years...the Sigma sparkle-finish coating will begin flaking off in five years. The Sigma will lose half its resale value in five years...the Nikkor will maintain its value, or even appreciate slightly over the next five years. I own three Sigma lenses currently, their 100-300 f/4 EX-HSM, their 180/3.5 HSM EX Macro, and their 18-125 DC. They all have the typical yellow Sigma color rendering, which is very much opposite of Nikon's cool Nikkor color rendering.
I dunno...the two-ring 80-200 is a pretty solid lens for $800-$900 in today's market....and it is> NOT< I repeat, is NOT, the first version of the 80-200 for Nikon....
Nikon 80-200mm f/2.8 AF-D (new)