bought most of my stuffs @ around $350 and held till now. I think you should always keep about 10% of your portfolio in gold. It is a hedge against stagflation / hyperinflation -- the economic data / trend now looks pretty similar to that of early 70's and gold sky-rocketed during the 70s.
Having said that it is not without risk -- the major central banks are still having a big stock of gold and each of them can sell about 500 tons to 600 tons per year based on the Washington agreement. I can't remember the exact figures but roughly speaking out of about 60,000 tons mined gold in the world, there is roughly 20,000 - 25,000 tons held in central banks (US / Germany / Switzerland being the biggest holders) and the rest is held by private investors / collectors. Draw your own conclusions.
My feeling is that long term I am bullish, and comparing to HKD / USD, there should be no match. Whether it can outperform good blue chip stocks is another story.