In the 1980s, a friend got his start by buying packaged software in bulk from the US and reselling it in Europe. The retail price differences were large enough

In the 1980s, a friend got his start by buying packaged software in bulk from the US and reselling it in Europe. The retail price differences were large enough he made bank on it. It's called arbitrage. Eventually, other people figured it out and the prices leveled out. Arbitrage opportunities crop up all the time.