The money part is true though, she wanted a pile of cash and they said "nope"

An agent might have been involved though so who knows if it was her or her agent making the demands. It has come up in the pinball world when they made the Aliens pin, they were in negotiations to use various actors and actresses voices including Sigourney Weaver's. Mind you this was just to use clips from the movies, she would have to do NOTHING but cash the check.

The number put forth from her representative was so ridiculous that they don't even have the character Ellen Ripley in the game.

Ghostbusters? She isn't in it, everyone else is including Ernie Hudson whom did custom pinball call outs for the game.