The original Bandai America release, Stadium Events, is widely recognized as the single rarest licensed NES release. A sealed copy of the game sold for over $20,000 USD in January 2011. The PAL release of the game is significantly less rare, but still a sought-after item, reportedly having sold for as much as $4,000 USD for a sealed copy. Some unscrupulous dealers have been known to try to pass off PAL Stadium Events cartridges as US release copies, so buyer beware!
The later Nintendo release, under the title World Class Track Meet, is relatively common in both territories and not highly-prized.