Except it doesn’t scale at all like this. There are companies selling sandwiches on private jets for $150/ea. Some people sell a candle for $5 at Target while others sell them for $45 at a farmer’s market. If you’re making websites for a living, it’s common advice to raise your prices to keep away people who aren’t very serious or who will balk at every expense.
There are countless companies working with excellent profit margins.
None of those are monopolies, unless you consider someone selling a sandwich on a particular plane as a monopoly and the people on the plane are your market, in which case it is exactly this situation, and why that sandwich doesn't cost $100.
So instead of trying to think of complications, you need to first understand the argument, and then you can see it everywhere once you understand it.