I think the problem is that you have two markets that are inaccessible from either. The business buy from one market, then sell on another market. And make a profit based on how inaccessible the two markets are to each other.
For example clean water can be very expensive where there aren't any, while basically free where there's plenty. So the business takes water from where it's free, then sell it where there's demand.
Back in the 1980's, software was sold packaged in a box. It was much more expensive in Europe for the same box sold in the US. Several companies noticed this and began buying up big lots in the US, shipping them overseas, and undercutting those markups.
The arbitrage was so successful the price difference was pretty much eliminated.
