You are also paying for marketing and R&D for every bow purchased as well.

It is no different than the automotive industry. A Mercedes and a Kia are basically the same. Both are sheet metal, both have tires, both have engines.

Do both get the job done? Absolutely.
Are there people willing to pay more to get the extras out of their vehicle? Absolutely.

It is a rather moot point how much it costs to make product "x." What matters is how much a business can sell product x for and maximize profits. I do not know how much it costs Mathews, Bowtech, or Hoyt to make their bows. I do know people are willing to pay as much as $700 for them, and to them they are worth every penny. What difference does it make if Beman sells arrows for $80 and hypothetically makes $60? That is capitalism, supply and demand. As long as there is a high demand for product x from company y, then they can charge higher prices. To me, the Bemans are worth it and I am willing to pay that much, but the Mathews are not (please don't attack me on that one, I said to me).