I remembered correctly: Titanium is incredibly expensive. I worked at a warehouse that shipped metal alloys, and one time I carried a big rod of Titanium into a truck. One of my more experienced coworkers laughed and said the bar was worth well more than any of us earned in a year.
Here's the first website I could find with Titanium pricing:
http://www.advent-rm.com/items.asp?c...enumber=TI2284
On that page, a 3.5 mm thick, 300mm x 300mm (between 1/8 and 3/16 inches thick, 11.8 inch by 11.8 inch) sheet of Titanium is $664. If you buy in bulk, the price per unit drops but not by a lot. To get 1 cubic foot of Titanium, you would need to get about 88 of those Titanium sheets and even at the discount rate it's more than $40,000.
There's a very good reason no automaker uses Titanium extensively in their cars. Even with economies of scale, it's monstrously expensive.