I thought I'd jump in for fun here and touch upon your question about the high costs of medium format cameras. As others have pointed out, they are larger, which means more material per camera, have technological aspects such as much larger sensors, and lenses that are also larger, thus more glass (and generally high quality to begin with)... etc.
So the MBA in me starts talking, and anytime you have companies producing products in lower numbers due to either their complex nature and lower demand, then you will see costs skyrocket; otherwise these companies would go out of business pretty quick if they sold these cameras for $4,000. Think of Ferrari or Bugatti. Superior in some ways to "traditional" cars and manufactured in small numbers = high price tags. And like most businesses in this category, I have a feeling these costs are also inflated somewhat. Like a Ferrari; I doubt in terms of materials they cost "that" much more... but there is an element of luxury to them.