regarding Batman and the overpower gaming cards, I recall back in 1995, they were tough to find. I think they were 1 per 5 boxes or so, and those were the days before ebay. So you had to rely upon the local card dealer breaking boxes to get them, or finding one on your own in the packs !

Charmed Season One & Power of Three.

Thanks for the info chesspieceface. The weird thing is, I didn't get a sketch when I opened the box, but kept two packs sealed. So one of these two packs must have a sketch in it!

Ohhhh-kay, talk about a "Hot" pack.
Those two packs (just to be safe) should be worth at least $150 or so, sealed as they are.
I don't remember any "dud" boxes of these, so one of them should hold a sketch.

Since they are your own packs, you can probably figure out exactly which one has the sketch in it without opening them. Since the sketch is on a flat stock card, the cards would slide a bit differently if pressed against one another. The value of the sketches (based on artist) range from about $40 to $500, which is what I'd based my $150 estimate on. The sealed box should be at least $200, easy. Stan Lee is the best autograph at about $100.