Volarecantare, they actually did not do as well as you think. If they just took the money they were paying for the extra tax, management fee and rates and invested it into the stock market for the next ten years or any other property market around the world, they would have made more money than 3 mil honkey today (as long as you sold out a few months ago).
If you purchased a 400,000 place in the UK, Aus or the Us back in 97, you would have more than doubled your money and with the exchange rates your probably would have tripled your money.
Just remember the Hong Kong market is driven by sentiment, and unlike other places it is timing that counts more than time in the market. The people that make the big dosh move in and out a few times in a rising markets and usually you will see their involvement at the beginning of the boom
Now I'm not saying that you must not use your housing allowance, all I want to say is that if you are looking at your house and a investment , then you need to make good investment decisions , which means buying and selling at the right time, and not just buying because you have a housing allowance.
The other down side of the guys buying in 97 is that they were forced to live in the same place until CX paid it off, as they had massive negative equity and very low rent , interest rates were as high as 9% possibly even 11% if I recall correctly).