Well, I've e-mailed them and they say that they think the game is original as they bought it from a reliable distributor. However they didn't open it as they would lose the warranty. The "low" starting price is because "they want people to bid and increase the price that should be 150-250 euros"
Here's one official cart:
And here's info from !arcade (Ray e-mailed me this link and told me the cart we discuss is a bootleg):
<a href="http://www.neogeousa.com/kof2k1/kof.html" target="_blank">http://www.neogeousa.com/kof2k1/kof.html</a>
The funny think is that !arcade claims this cart is legit:
That is almost identical to the cart we are discussing, but it has "fighters" instead of "fighter". However the label is very different from the white one,as it has a space between fighters and 2001 and says SNK.
Finally there's another thread about this:
<a href="http://www.neo-geo.com/cgi-local/ultimatebb.cgi?ubb=get_topic&f=18&t=004957" target="_blank">http://www.neo-geo.com/cgi-local/ultimatebb.cgi?ubb=get_topic&f=18&t=004957</a>
Well, I guess the veredict is that the cart is most likely a bootleg. However according to !Arcade boots of KoF 2001 work OK as the original. Is that true?