Well, now knowing that BF4 is coming out in the foreseeable future I would hold off honestly.. Should you buy a game? Sure? The game is fun, even better if you have a group of friends to play with and work together for an objective. I'd say if you buy the game, then just buy the thing that includes all of BF3+Expansions. Hacking is not that big of a problem either. I've run into maybe 4 hackers in BF3 in a total of a year/half ish. Buy the game if you want something different. I would.
Battlefield 3 Premium Edition (Includes everything) is around $40 last I checked. Sure you can wait for some deal ORIGIN might offer down the road.