Re: Buying Sims 3 expansion packs through Origin.
@CinderellaGirl91 Yes, absolutely. As long as you buy the games on the same account where you registered your disc copies, all of your content will be available for download in your Origin library.
Just a note: Steam is currently offering a sale on all Sims 3 packs: $5 U.S. each. (The sale ends January 3rd at 10 am PST/6 pm UTC.) You'd have to buy the base game in Steam first (another $5), but you'd pay $15 total to get the two packs instead of $40 through Origin. Steam provides codes that you can register in Origin, just as you registered your disc codes, and then the packs will be added to your Origin library as well. You'd also get 1,000 SimPoints (for store content) for free if you registered the extra base game code.