The rarest thing to find in HK is Mixed Spice, not 5 spice which is a different mix and on the sour spectrum. Mixed is on the sweet side.
Anyway over the years I have travelleled all over HK and never got it reliably. HOWEVER .... discovered a Spice company in Tsuen Wan, online, who make an Xmas mixed spice and seem to do all the spices for any occasion.
Now, Geoexpat usually block it if you mention the name of the company so Google Tsuen Wan Spices and you should get it.
Ordered Thursday night and arrived this morning by courier and if I had ordered 100hkd worth the delivery would be free instead of the 20 bucks. Oh and they do 5gm sample sizes which is great for me as a cake will only normally take about half that.
The price for a 40 gram jar was what you would pay in a supermarket.
So great product, great service. Refreshing to have this and ready to bake my Xmas cakes.