Short answer: Based on my shopping over the past few months, that price is within the range that these cars usually sell for.
Long answer: That's not a "bad" price, but there are several variables...
- What is the general condition of the car? (interior, exterior, and engine)
- Does the owner have service records to indicate that the car has been taken care of?
- What is the mileage?
- Is it a Base model, or does it have the Active or Sport package?
- Does it have any features that typically add value? (e.g., alloy wheels or California Roof)
You also have to determine if the car is "what you really want." E.g., if you know that you want a 318ti with the Sport package, and the car in question is a Base model, you probably won't be satisfied with it regardless of how much you pay for it.