[AZLiberty]

No doubt scaling is a issue, but Nanosolar is already at the level of mass manufacturing, with a plan to produce 430 MW over the next year. According to this article:

"What makes it also cheap are the materials used in it’s productions, being made of an Aluminum foil for stability, Molybdenum electrode, an ink made of indium, copper, selenium and gallium, a semiconductor that doesn’t absorb light and a clear Zinc oxide semiconductor."

My engineer brother has suggested that Nanosolar and similar sheet-based solar technologies may be a reason that the price of molybdenum has gone up by a factor of 10 over the past year.

[AZLiberty]

Shows what my brother knows. The price of molybdenum doesn't seem to have changed that much. It started the year at $28, and seems to be at $34/lb now.