I have a MINT condition cartridge of Clay Fighters Sculptor's Cut for the N64. It originally was a Blockbuster rental exclusive, but I found a copy that had no label peel and no sticker residue which is almost unheard of. The guy I bought it from used to be a manager at Blockbuster and he said corporate sent his store two copies and he only ever put one "in circulation" and kept the other behind the counter - mostly because nobody in our small town was renting Clay Fighter so he didn't see a need to put stickers on it and put it on the shelf.
Not too long after, Blockbuster corporate told him to clearance or junk the N64 section, and he "bought" the mint copy off the store. A few years later, I bought it off him kind of as a novelty - this was back when the game wasn't really worth much.
I know there were originally 20,000 copies of the game made - but I have to wonder sometimes how many are still in existence / collector's circles. Searching on eBay leads me to believe it's worth a couple hundred dollars. I'll try and snap some pics of it when I get the chance.