Well ... get the car you
want. I know that sounds dead obvious but there's a reason for that
Not buying a car because it might be replaced in a year or so ain't a good way to buy cars because you'll never buy a car unless it's brand new. Sounds to me like you're trying to get someone to talk you out of going for the less practical, more fun 135i and talk you into the more practical, less fun 328i. I'm not that person.
I reckon you
want the 135i