The upfront costs for a custom ASIC manufacturing line at the 135 nm levels are between $2M and $3M, for design, tooling, masks, testing, repairs, packaging, more testing, and the whole semiconductor fabricatoin process.
I think if the VCs were offered 10x their money tomorrow, they would probably take it. So you're looking at $20M-$30M. Once these start shipping, the value of the company will be even higher.
I predict they will be the largest bitcoin company in 2012, surpassing Mt Gox and BitInstant in revenues.
I guess it makes sense that a mining related company is the largest. Though mining is the least interesting thing about bitcoin.
If I was i-q-tel I would be buying bfl.
http://www.iqt.org/about-iqt/history.html