Don't compromise because of budget constraints....just find a 35i CPO or off lease deal somewhere. There are tons of these cars out there.
If you settle you'll regret it each time you see a 35i badge on another X3.
But if you have to have a new one and the 28i is the only way to get you in the seat of an X3 then pull trigger. Make sure you do a PCD.....its so worth the trip.