@RandomTokenCode There's currently an issue with Roaring Heights that makes it difficult if not impossible (I'm not sure which) to actually add the world to your account. The safest approach would be to buy a new, sealed physical copy somewhere and—this is critical—register the product code on the old Sims 3 site, not in Origin. That's the old way, and it should still work fine.
If you do buy RH through Origin, you'd still want to register the product code on the old Sims 3 site, but I've seen multiple reports that it doesn't work properly now. In that case, just be sure to test it right away and contact EA customer support immediately if you run into trouble. You should in that case be able to get a refund, so all you'd lose is a bit of time. The issue isn't the points but the world itself; if you did happen to get the world but not the points, a support rep could add them to your account easily enough.