@Notfallkaramell The discs for expansion and stuff packs are usable without their being registered if, and only if, you also have a base game disc that doesn't require Origin. It's definitely possible that the disc only tried to use Origin because the app was still present on your computer, so it's worth trying again once Origin is uninstalled.
The other option is to login to the EA App using that old email address, if you still have access to it. The content should all be in the game library tied to that account.
@Notfallkaramell I'm sorry to hear that. I guess your best bet is Steam then, during a sale. The base game might still be full price, so be sure to check the "Sims 3 Collection" price too.
