Let’s see...

We go to Canada. The U.S. prices rise. More go to Canada. The government steps in to "correct" the problem. Canada is forced to pay a true R&D price for U.S. drugs. Prices rise in Canada. Prices fall in the U.S. People return to U.S. purchases. Canadian citizens are again pissed with their neighbors.

Or:

We go to Canada. The U.S. prices rise. More go to Canada. The government steps in to "correct" the problem. The borders are closed to all drug traffic*. Canada's prices remain fixed, and people are forced to return to U.S. purchases. And prices in the U.S. will no doubt continue to rise to cover R&D research -- which will continue to become more and more expensive. U.S. citizens are again pissed with their neighbors.

* not including drugs U.S. citizens might purchase within Canada for use for travels within Canada

Dan