Drug reimportation is actually a very complex issue and the savings are unclear:
Here's a good NIH overview on it:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1936287/
I dont think it is as complex as the govt wants us to believe. They claim they ban the use of US manufactured drugs from being reimported due to safety concerns. And the economists they reference claim the economic benefits may not be as good as believed. But they also claim US manufactured drugs being purchased in Canada for 20-80% less than the cost in the United States. It doesn't take an economist to see the economic benefit for those purchasing that drug.
Anyway my point is we have a protected market that bans a free market on prescription drugs. The result is very high cost of drugs compared to the world.