Tell your mom to stop that. She is throwing away a fortune. Gameboxes are collectibles, and can sell for an awful lot just a few years into the future.
For instance, Taikara has a complete set of Sierra Quest boxes in prime condition, along with every manual and even a 300+ pages King's Quest "player's guide". If she were to sell that (something I hope she won't :P) she could make several thousand dollars on them - and the games are just a bit over 20 years old
So the bottom line is: Tell your mom that she is throwing away your college money. Parents don't really know the value of computer stuff, so you need to inform them.