The expense covers a great many things.
- Manufacture cost, obviously.
- Company profits.
- Company overhead (the lights, the IT department, and all of the other stuff not directly involved in making pumps).
- Research and Development, which leads to newer, better, fancier pumps.
- FDA (and other countries) testing/trials, which can cost millions.
- The costs to run the 24-hour support lines pump companies maintain.
- The maintenance overhead from replacing in-warranty pumps.
- Marketing and promotions.
- Insurance processing, paperwork, and discounts.
Now, your car probably has many of the same costs. But they sell way more cars than Medtronic can sell insulin pumps. So those costs get spread out, leading to a smaller cost per unit sold (except for the actual manufacture costs).
Also, many of the repair, maintenance, and support costs are actually assumed by local dealerships and so less of that comes back to the Honda corporation, for example.
Yes, they are way too expensive. But there’s more than one reason for that. And no easy way to fix it in the USA. Not without some major changes to how we handle health care, at least.