How many times can cdf members buy?

Cdf members can purchase unlimited times. There are restrictions on the types of duty-free goods that can be purchased and the quantity of each purchase. For example, cosmetics are limited to 30 pieces at a time and mobile phones are limited to 4 pieces at a time. The algorithm here is that passengers leave the island by plane, train and ship after shopping, and it is recorded as 1 duty-free shopping.