there were alot of these cards, and scoreboard cards that were released unsigned, people snapped them up and put their own signatures on them. There are real ones about, but its a risk to buy in my opinoin
there has been alot of those on ebay over the years and they barely ever sell for over $50. In all the time i've been buying Kobe autos i've never even thought about touching 1 of those. As people have said if it seems to good to be true it normally is. Older sets IE Scoreboard sold alot of cards unsigned and lead a big flood of fakes that are still floating around.
These Scoreboard cards are crap, sooooo subject to counterfeit copies. Stick clear of them just to be on the safe side. I believe there ARE legit ones around, but pretty rare, as there's too many fakes.