Hong Kong has no shortage of real estate developers and agents promoting offers to invest in overseas properties. From time to time when I have nothing better to do I go to one of these exhibitions as a form of entertainment and as a means of learning a little bit about other markets. While there have been occasions when I have been tempted to buy, I have never done so. My reasoning is essentially:
1. it costs a lot more to market a property in an overseas market. Someone has to pick up that extra cost, and it usually ends up being the buyer;
2. if the developer could sell the property at the same price in the local market, why would they bother marketing it in Hong Kong? The short answer is that they increase the price when selling overseas properties to Hong Kong based buyers. I usually don't bother, but on one occasion I asked a friend who was living in the city where a development was being built (Melbourne) to check the prices being offered to local buyers. The prices being offered to Hong Kong buyers were typically 3-5% higher than the prices being offered to local buyers (if I recall correctly). On another occasion, I was with a friend who already owned property in the relevant city (London) who told me that what was being offered to Hong Kong buyers was "far too expensive" for the location and type of property;
3. as a foreigner you are more vulnerable to other types of scams and your own ignorance than local buyers.
If I want to invest in an overseas market, I would favour going there in person and doing a lot of research first. Even then, while investing in other cities can be profitable and can help to diversify a portfolio, managing properties long distance can be challenging and will definitely involve more hassle than investing locally. As a single example, you will have to familiarise yourself with a new set of tax laws.
The only overseas properties I own are in a city which I (i) know very well having lived there for a number of years and (ii) have relatives living who can help out if necessary. I have been tempted to invest in other cities (London, Shanghai and Bangkok (during the Asian crisis)), but have never quite managed to overcome my worries about making a sizable investment in an illiquid asset in a market in which I have significantly less knowledge that either local investors or the vendors.