Well those aren't really fair comparisons. I don't think Tourneau even carries PP, but even if they did they are probably the worst place to buy a watch. I certainly not in a position to buy a Patek, but having bought a few higher end Swiss pieces in the past couple years I think there are two things at play here. If your ready to buy a PP I would imagine you have a local jeweler either in HK or state side that you have purchased other pieces from. This would be your best bet. Somewhere like Hamilton Jewelers in Princeton stateside is a place that sells PP and a place where you can build a good rapport with a particular sales person. That's where you can start to see pricing that is clearly not advertised, and in some cases the sale is dependent on being asked to never disclose what you actually paid to anyone else. Receipts and such reflect not what you paid, but what a normal transaction should have looked like. I can't imagine that if you are seriously in the market for a PP caliber piece you don't have a relationship like this.

The second point is it's Patek so there are no rules. What kind of watch are you looking for? A Nautilus in stainless steel, a calatrava, or a complication piece? All three of these watches have entirely different buying processes. Pieces in steel can have waiting lists that are years long. And at the extreme 7 figure end of Patek you have pieces that require first time buyers to submit applications to corporate to show you are a "worthy" buyer.

All of that being said. I have priced out high end watches in Hong Kong, Tokyo, and Bangkok. I have always found that the prices can be beat in New York. Although again Patek is a very strange bird in my experience.