Also available at Tiny Footprints (when in stock), baby online hk and I'm pretty sure I've seen it for sale behind counters at 'Fusion' stores on Caine and Robinson Rd, Midlevels as well as 'olivers' in Prince's building
I have seen it at Taste, about HKD$ 300 per can. I find it ridiculously expensive. Luckily I bought 12 cans with me when I moved to HK from Australia. It is about HKD$105 per can over there.