If I buy Battlefield 3 premium on xbox live do I need the original battlefield 3 game/disc or does the premium on xbox live come with all of that?
Yes you need BF3 to play premium. the cheapest way to do it is to buy BF3 premium edition in a retail store, they were like $25 on black friday.
I don't think they have the premium edition of the Battlefield 3 on the marketplace, so I'm going to go with it's just premium subscription and you'd need Battlefield 3 base game to play.
Edit: Just checked it's just the subscription. If your want the Battlefield 3 Premium edition (Base game and premium subscription) you'd have to buy if from a retailer.