1. Original Tamagotchi
If you were a child in the '90s, you know how hard these little eggs were to take care of. You probably killed your Tamagotchi a few times and had to reset it, but you loved that little toy. If you happen to have an original Tamagotchi, you could make some money off of it.
A Tamagotchi still in the box could be sold for $3,000. The company launched a whole new line of Tamagotchis that have colored screens and can connect to a mobile app. It is probably a lot easier to take care of them when you can access it from your phone.