Here's a typical Causeway Bay Mainland shopper. They often come in just for the day and buy a suitcase as their first purchase, so that future purchases can go into the suitcase.

TUNG’S TRAVEL JOURNAL: How a shirt goes from $30 in San Francisco to $89 in Shanghai

Having Mainland Chinese relatives and Mainland Chinese international students at school has given me an interesting window into their consumer psyche.

For one thing their psyche is very different from even my Hong Kong relatives. When I took my Mainland cousin Candy to the Galleria, she stayed there for five hours. After that she still had to do a three-hour romp through the outlets in Folsom before calling it a day and driving off to San Francisco for another marathon shopping session.

I always thought my cousin was crazy.

Junior Manson Tung will be teaching at Hong Kong Summerbridge from June 21-August 15. He will be writing periodic blogs about his experience living, working, and traveling around Asia.

I also rolled my eyes when I discovered that some of my Country Day school friends packed entire suitcases filled with luxury products to bring back to the Mainland.

You could imagine my incredulous face when my cousin Vicky got into the same business. I can’t look at her Wexin—Think Facebook Messenger but with a lot more users and all in Chinese—page without getting an eyeful of Louis Vuitton and Juicy Couture.

But I now have to apologize to all those aforementioned people. Why? I have seen why they were shopping in America.

Welcome to the People’s Republic of China, where the tax on imported luxury goods is likely around 100 percent.

My first shock came at Armani Exchange. In San Francisco, I almost picked up five graphic T-shirts for about $30 USD each. But the friend with whom I was shopping with said, “Think about it. Buy it when you’re in China if you still want it,”  because I already was loaded with shopping bags.

When I went to the International Finance Center mall in Shanghai and saw an Armani Exchange, I knew that I still wanted those shirts, mainly because I had taken “pack light” to an all new level. Turns out that in Asia, people air dry their clothes, so laundry takes a day or two instead of two hours. So my five days worth of clothes had suddenly became three.