Maryhinge,
my advice was given to me by the Breitling watch repair centre that is in the Shun Tak centre, where the Macau Ferry runs from. That not all the Hong Kong shops are the best retailers. The reason being is that they sometimes get stock from other parts of the world, in particular the less popular models from other regions will have sat on shelves and in stockrooms. If they are over a couple of years old and they are self winders the mechanisms can sieze up. Always check the manufacture date and the intended sales region which is punched in the back of the warranty card
The best suggestion is to call them up or go and visit them, they are very helpful. And they will advise the most reputable dealers.
Other than that, I bought mine in Dubai, cheap price, new model. Very happy.
Good luck.