This whole thing makes me wonder. Hong Kong imposed a 2 tins per person export limit with huge penalties. Five or so years back when their shelves were being picked clean, this made sense as an emergency measure. What makes no sense to me is that the never bothered to change it. Why not increase the imports to HK and raise the limit to 3 cans? Then, once supplies are stabilized, repeat the procedure to raise the limit to 4, then 5, etc. As imported supplies increase, those big markups in China will shrink to more reasonable levels.
Hopefully, the Australian stores will see this as an opportunity and increase their orders to their suppliers instead of complaining about any specific group of people buying too much.