The slightly dog-eared, exhausted NES cartridge you see before you might not look up to much, but it's got game collects the world over salivating at their keyboards.
eBay seller and collector of all-things-NES 'muresan' claims that this faded grey relic is a Nintendo World Championship Cart - a game cartridge made for Nintendo's 1990 world championship event, at which gamers were able to compete on minigame editions of Tetris, Super Mario and Rad Racer.
Players had six minutes and 21 seconds to score points on each of the titles, competing for a top prize of $250 and a trip to Universal Studios Hollywood.
Only 116 of the cartridges were made for the event, and given that they weren't sold to the public (90 of them were given to semi-finalists), collectors view them as one of the rarest ever made. In 2011, one sold at a charity auction for $11,000.
Due to the damaged label on muresan's cartridge (he notes that someone didn't know what they'd got their hands on, scribbling 'Mario' in ballpoint pen on it), it's currently going for a far more reasonable $5,600.99 (£3,329.69). You've got one day less to pick up the bargain of the year...