I walked with numb feet down the Great Wall, which the cold had left so deserted I hardly recognized it. Unlike all the sane people who stayed home, I decided to brave the winter wind so strong it knocked me over, just to take my sister to see the world's greatest wall.

As we approached a watchtower, we saw something we hadn't seen so far on the wall: a vendor.

She stood next to the watchtower, bundled in a large red coat and scarf, selling small gold-colored Great Walls to anyone walking past. When we came within earshot, the woman set her sales pitch and sang: "Liang kuai, liang kuai! Five! Five!"

Being a white-faced foreigner in China, I reap undue benefits galore. I get guest-of-honor status in small town restaurants, where I've had to argue with locals who insist on paying my bill. I get frequent and hearty "halloo's" when I walk on most streets. And I'm lavished with effusive praise for my Chinese skills before I can even get past ni hao. But of all the benefits, my favorite is preferential pricing for foreigners.

Preferential pricing, like prejudice, is often hard to prove. But the gall of this Great Wall vendor made me laugh. In the same shout, she had declared that the Chinese price was liang kuai, 2 yuan ($0.29), and the English-speaking price was 5 yuan - more than double.

When my cousin - who speaks excellent Chinese - asked her about the obvious discrepancy, the woman came up with an excuse, saying she was referring to different sizes of the trinkets. This was despite the fact that there was only one size in her cardboard box.

In China, foreign guests have the honor of paying all sorts of special fees because of the color of their passports. When I took a local bus to a remote Yunnan hiking trail popular with foreigners, the bus stopped right before an iron bridge crossing a stunning canyon. A young man in an unlabeled uniform trotted out from a one-room office next to the bridge and stepped onto the bus. He scanned the passengers and marched over to my seat.

"You must pay the bridge fee. 100 yuan."

I protested, but the man would not budge. So I paid and the bus rumbled on.

The concept of special foreign prices isn't limited to China. I saw one unabashed sign in Laos at the entrance to a waterfall that read in English: "Foreigner price: 5,000 Kip ($0.59). Local people: 3,000 Kip."

I'm told that in some countries, airlines charge foreigners more for the same tickets. But if you can't jet around the world, don't despair. The practice of overcharging outsiders is so universal you don't need to travel to the other side of the world to experience it.

I've fallen prey to the foreigner price fix without leaving my home country. My sister and I bought some famous South Carolina peanuts at a stand on the side of the road, where we had the honor of paying the northern accent tax. At least, that's the only explanation we could come up with for why we paid twice as much as the southern customer in front of us.

So, it was hard to be too upset with the tough vendor on the Great Wall when she so nonchalantly tried to gouge us. At the very least, she was embarrassed enough to come up with an excuse for her trick. That's at least a step up from the unashamed sign in Laos.

And for most foreign vacationers, paying an extra 3 yuan would mean far less than it would to the vendor. I, for one, would be willing to pay an extra 3 yuan for the chuckle that the woman's chutzpah gave me.