Ofcourse, the big news out of the GigaOm interview with Musk is the Model X reveal. But here is something interesting. I've been thinking for sometime that the battery price will halve every 5 years. We had some discussions about it in a different thread. 12 tech leaders Tech News and Analysis The difference between selling S & Roadster is roughly 4 1/2 years (Feb-2008 to Jul-2012). Musk says the cost actually decreased by more than 50%. Ofcourse, it is possible he is comparing the cost now to something much earlier than Feb-2008. Still, this is instructive. If we take his 9% per year cost reduction, we get to 38% reduction in 5 years.