That is only a few markets, in one of the wealthiest countries of the world. In the rest of the world android is pretty much +%90 and iphones are luxury goods, like a designer handbag or a porsche.

Apple is definitely the Porsche or Mercedes of computing.

Do they buy it outright of pay a fraction of the cost upfront then overpay for it on expensive monthly contracts? I very much doubt most of the 50% US market aren't tied into 24 month contracts.

Why does that matter? It's an interest free loan and they eventually do pay for it. We don't criticize people for buying cars with loans or even houses. When we purchased my dads car we were going to buy it cash but we got a 6 yr loan at 0% interest so it was a no-brainer to do that. Additionally most carriers now are offering incentives when you're on their payment plans. If your argument is that you should ditch your current carrier and use some cheap MVNO service instead then that's something entirely different.

Does it matter? There is no such thing as “overpriced” for products that fly off the shelves except only in one’s personal opinion.