Actually, you are 100% wrong, and you know it. The KOF 2000 US was NEVER in question when Playmore tried to sue NGF. This case was over copyrights and they lost - badly. Maybe you have not seen the press release? The one that Playmore had ot post on their website saying every cartridge NGF corrected was authorized and official?
http://web.archive.org/web/20050208171535/http://www.snkplaymore.jp/information/en_press15.html
As for the KOF 2000 English, the most investigated game in history, it has been known since release that the game was 100% official, true SNK Japan produced and shipped directly to NGF. Many many people called SNK Japan directly at release and it was confirmed of course.
As far as the value, $8500 is nowhere near out of bounds, as even on ebay, where prices are low when it comes to items like this since the buyer cannot be sure of the source.
Here is just one steal of a deal:
http://www.ebay.com/itm/15079956227...AX:IT&_trksid=p3984.m1423.l2649#ht_500wt_1182