Thanks to our pal Tad who passes along a link to this list of 8 rare and expensive video games. An example:

3. Nintendo Campus Challenge (NES)
Price Range: $14,000 -- $20,100

Why So Expensive?: In the early 1990s, Nintendo held competitions on college campuses and at popular Spring Break destinations. Like the World Championships, players had six minutes to play for high scores on demo versions of Super Mario Bros. 3, PinBot, and Dr. Mario.

Most copies of the game were destroyed after the competition ended, but one Nintendo employee kept his cart and sold it to Rob Walters at a garage sale in 2006.

This garage sale is legendary among retrogamers, as Rob bought all kinds of NES Holy Grails for only $1,000. By the time he re-sold everything, he'd made 50 times that. Part of that $50,000 was the Campus Challenge cartridge, which went for $14,000. Shortly after, the buyer of the cart turned around and sold it on eBay for $20,100. As far as anyone knows, it's the only copy of the game in the world.

Cool story, worth your time for sure.