The problem is Nike have probably produced literally thousands of different items of clothing since the early 1990s. This is likely one of them, on the balance of probabilities probably not fake - but if it's pre-2000-05ish it probably never existed "online" and even stuff after that can disappear very quickly, and only a limited number of very popular/iconic pieces are well catalogued. It's Nike, so original price isn't likely to have been that high, they're a solidly mid market brand.