Adult game on Famicom sells for 499,000 yen
An old cart of the Famicom game Super Maruo had sold for 499,000 yen (4,100 USD) on Yahoo Auctions a few days ago. According to this site, Super Maruo was the first adult game to be (illegally) released for the Famicom on Dec 1986.
It was apparently very badly made and had very little content but they sold it for 6,800 yen, resulting in very low sales and thus also making this one of the rarest carts out there for the Famicom.