Skip Rung of the Oregon Nanoscience and Microtechnologies Institute (ONAMI) wrote an interesting article today in Nanotechnology Now about how to make nanomanufacturing lean and green with a mention about materials for a space elevator. Here's an excerpt:

"Nanotechnology (which mostly means nanomaterials) has its own related issues. I heard a presentation today (a good one) by a company that produces or is developing grades of carbon nanotubes ranging from $50/g (for a somewhat mixed grade of material with residual catalyst impurities) to $200,000/gram for the ultimate in selectivity and purity. It is somewhat doubtful that the space elevator cable can afford the former price, but not doubtful at all that the higher figure is out of the question. Those familiar with the fabrication details of nanomaterials know that achieving high purity and uniformity is difficult and expensive."