Another good example. Thats why I still have all my original NES games with the boxes and manuals locked away in storage. One day I will sell them. and hopefully make a good profit.
Most NES games are completely worthless (like $2 apiece). The boxes and manuals typically double the value of the game except in some cases. My copy of Action 52 alone is worth about $80. With the box and manual, the game's worth skyrockets to around $200-250.