I've used a 2011 X1 for full 2 years and did in excess of 30000km in it.
It did way more than 8km/l when I used it. In long trips I always got over 16km/l. In colombo it was more like 10-12.
If you can buy parts from singapore, then nothing to worry about. by parts I meant brake pads, rotors, and other wearables. I have no idea about damage repair cost or mechanical defect repairing costs. It was so good to drive, awesome car to own and economical on fuel. But it can be a little hard to manoeuvre around town due to heavy steering. Perfect for 4, but carrying 5 is kind of not comfy. For a diesel, the engine is very refined and powerful. Cabin is quiet. I would like bit more equipment in it though as all it had was the bmw business radio. But who cares, it's a beemer and the chassis is the magnificent E90 chassis. What you have to worry is the cost per service, if u r planning to take it to the dealers. Go buy one. One of the best cars 6mn would buy u. Please let me know if you want to clarify anything.
Xtrail or any other jap would not give the same thrilling drive, but they could be less expensive to maintain if u chose non OEM parts. Well I do think BMWs are as reliable as its japanese counterparts. At least the new ones
PS: If you are not strictly in to a crossover, there are some good Audi A4's lying around for that money too.