What is the best and cheapest thing to buy in Hong Kong?

I think it's best and cheapest to buy these things in Hong Kong.

1, medicine, these pharmacies are like shops selling souvenirs and specialties in tourist areas.

2, cosmetics, not only the quality is guaranteed, because it is tax-free, and the price difference with the mainland is very large.

3, jewelry, gold jewelry stores in Hong Kong can be described as dotted.

In terms of types and models of digital products, Hong Kong ranks among the best in Asia.

5, sports and leisure products, almost all sports goods and equipment can be found here, but the most is sports shoes.