Toyota RAV-4 or BMW X3?

My Mom is looking to buy a car around 15K-18K with low Millage. She likes crossover SUV s and i found that the two cars that interest her are the RAV-4 or X3. I found that you can get a 04-05 BMW X3 for around 18k and an 06-07 RAV-4 for around 18k. So which one should she purchase.
Things we are considering:
- Resale Value
- Gas Millage
- Comfortable Ride

Any Help Appreciated!