I never knew this. Stadium Events, that rare NES game by Bandai, could be kinda...not...rare if you get the PAL version. The NTSC version hit the US, but then was discontinued, making it more rare. Blog Video Game Price Charts lays it all out with a diagram. Long story short? If the name "Stadium Events" is all on one line, it's the rare NTSC version, being worth up to $13,00 if complete. The PAL one has the name split over two lines. Even complete, the latter is worth hundreds, and not thousands.
Now take what' you've just learned and tell me if this eBay auction is worth the current bid price of $7,100.
I would never pay over $50 for a NES game (more like $5 in honesty), but for those that would, this is nice to know. Thanks for the education, JJ.