I can't recommend the BMW x1 enough. It is such a lovely and a reliable vehicle to own. Try to get a good company maintained low milage version (below 50k kms) if possible. Below are some of the points I recommend. (I owned one for 3 years and still misses it after upgrading)
Be sure to maintain it at agents, it is important when it comes to reselling the vehicle, but also take opinions from other popular BMW garages in colombo - I am not sure if you'd be able to maintain it outside colombo.
No faults to watch out as much as I know, BMW recommends all N47 engines to have done a measure on timing chain - agents do this FOC if the vehicle is maintained under them.Chances are a vehicle you buy these days may have done it already. But check that anyway.
It does pretty well on Fuel - mine did about 10kmpl in colombo and 17 on highway. ( of course you would need to pump super diesel)
Parts are somewhat expensive, all break pads and disks (front and rear) costed me almost 200k. a BMW AGM battery that would run you for over 5 years would cost about 100k as well, but if it has been replaced recently with a genuine AGM battery then you wouldn't need one for 5 years.
It is not a vehicle to do off roading, in normal driving conditions around SL, I've never had an issue where ground clearance was an issue.
All in all - it is such a wonderful vehicle to own around that price range. You feel good driving and owning one.