The Canadian dollar

For the last week, the Canadian dollar (affectionately known as the loonie) has been trading at par with the American dollar. That hasn't happened in the better part of thirty years. The result is a rush to the border for those searching for bargains.
What I can't understand is why the same item is so much less expensive when purchased in the United States. More than sixty percent of the time, that product was manufactured in Canada in the first place. Even if that weren't the case, the price difference is sometimes beyond belief. Books are a prime example. On average, a hardcover book can be up to twenty-five percent more expensive in Canada than in the States. What is the deal with that?
Of course, currency is going to become obsolete one of these days. As it is, most of the money that trades hands is "imaginary". It is all just numbers in a few computers. Aside from vending machines and certain coffee shops, there really isn't a need to carry cash anymore. Everybody uses debit cards these days. In the future, I see secure biometrics being used, your fingerprint is your bank account access.
Why should we bother with exchange rates? It is a global economy, despite the protests of certain extreme groups. Perhaps it is high time that we acknowledged the fact, and came up with one global currency, something that we could all agree upon the value of. When resources are harder to come by, the currency would be worth more, reflecting the amount of effort to produce goods and services.
If we are going to argue that people should be thinking of the environment on a global scale, then maybe we should think of the global economy, the resources that link all of us.
I am very much an idealist. On the other hand, I know just how much stands between an ideal world and reality. Just putting it out there for consideration.