Comparing MF and 35mm will always be like comparing apples to oranges, but sometimes, and orange will do the job if it's considerably cheaper than the apple and money is a question. I was just pointing out that comparing a D3X to a Pentax 645 isn't more relevant than comparing a D800 to the Pentax. Rather the other way around actually, since the D800 is closer in megapixel count.
The megapixel count alone does not determine the cost (or quality) of a sensor.
Irregardless, the only motivation medium format would have to reduce pricing further would be that the price reduction would result in X times more sales than resulted from the previous price level. And if that is not likely, it is not going to happen. It can be a risky strategy. And also, that the price reduction would not negatively impact the pricing positioning of their products relative to each other. Manufacturers do not price their products solely on costs plus X amount of desirable margin. They often employ a "pricing structure strategy" for the entire product line from the top end to the bottom, as well as with respect to each product segment. This is illustrated by the relatively stable pricing levels and hierarchy of many company product lines, notably Canon, Nikon, Phase One, etc.
Canon/Nikon mainstream professional (5D-MKII/D700): $2,500
Canon/Nikon specialized professional (1D-MK/D3): $5,000
Canon/Nikon top end specialized professional (1DS-MK/D3X): $8,000
These price levels have remained fairly constant, while models at each level have updated over 2, even 3 generations, though it appears the new models from both companies are slightly re-shaping these structures.
A similar structure is in place with medium format. Traditionally, it was:
Medium Format Good: $20K
Medium Format Better: $25K
Medium Format Best: $30K
Until the P65+, this was the maintained pricing hierarchical structure for at least several generations prior.
With digital technology, these pricing structures will change and adjust, but will still generally stay in place for perhaps 2-3 generations, after which point it is natural that either changing costs (can be lower or higher), as well as developmental advancements will disrupt these structures. This is potentially occurring now with Canon/Nikon and has already happened with Phase One/Leaf.
Steve Hendrix