I recently got a Sharp Twin Famicom for around 70€. This is rather cheap, they usually go for over 200€ in good condition. The Twin Famicom is a Famicom with a built-in Famicom Disk System drive. This was a floppy disk system for the Famicom that was only used in Japan. The one I got worked well with carts (at least with 8BIT MUSIC POWER FINAL), but disks wouldn’t read at all.