On my flight down to DC a couple weeks ago, I met an arbitrageur. It was in fact the guy sitting next to me, a Canadian driving to Buffalo to take a flight down to North Carolina to buy a truck that he planned to drive all the way back home to...Canada. He was casually indifferent about the whole thing, as if this was a run-of-the-mill endeavor. But really, why go through all this trouble?
At the time, the US$ was worth 92 cents Canadian (CAD). Yet car salesman in Canada hadn't adjusted to the new rates. They were still selling cars at rates about 1.5x the US dollar, which matched the exchange rate almost 4 years ago! A Chevy Silverado that cost around 42,000 CAD was selling for $30,000 in the U.S. My fellow passenger looked to save over $10,000, no matter how you measure it!
That's arbitrage for you; exploiting a price differential between markets. Just because the Canadian auto market is inefficient doesn't mean a consumer needs to lose out. Simpler examples of this concept can be seen at checkouts where all the lines are usually the same length because if one was shorter, someone would leave their spot in the longer line and move to the shorter one. Or in traffic, where all the lanes move at about the same speed, because if one moved faster enough people would switch over until the speeds matched once again.
This is also a great reason not to buy into all the investment advice by so-called "experts" (who are no better at picking stocks than monkeys anyway). If they really knew about the "hot" stock, wouldn't they have told their families and buddies first before informing you!? I'm sure the suggested stock is doing well, but who catches the windfall? The first people to get there. The first to find the shorter line or the faster lane. After that, any major gains are absorbed into the market leaving very little benefit behind.
So my friend in the seat next to me saves $10,000 and enough people will do what he did until Canadian car salesman realize they're losing out, or American car salesman raise their prices.