While looking around the KR-2 homebuilt aircraft site I found this link to AircraftSpruce.com
If you go all the way through to the online catalog they have sitka spruce available listed under spar stock. It seems kinda high. I just did a test order and a 1 x 6 x 12' was $97.20 which works out to $16.20 a board foot.
Thought you might want to know.