So you are buying a car which is almost 10 years old, the chance that the car needs major repair work is not low.
Your spending of 1500 USD in the states means the car didn't have any major issue, and that's only about regular service. For example, for e46, the surely-will-happen problem is the cooling system. I did an overhaul myself (waterpump, reservior, pulley, belt, thermo, coolant) and the parts cost 1k usd.
There are a couple good parts shop (Valiant) and you can easily access cheap quality parts. For example, 7 liter of BMW oil and an oil filter cost 535, then you can find any gas station to change for you for 250. For this kind of service you probably prepare 3-5k per year, you know, tire, brake, oil, all filters.
But if anything really breaks, VANOS if you know what I mean, sub-frame (US had this "recalled"), cooling system. It may cost quite a bit. But it's really hit-or-miss.
Anyway, owning a car in HK isn't cheap, tag and insurance cost 10k, parking easily 10-30k, gas/tunnel... I really don't think repair gonna be a major component on the bill. Labor isn't expensive at all if you can find a reliable garage.