That particular piece I bought locally, but I paid way too much per square foot. I have seen good prices on ebay for all kinds of leather, but I plan generally to order from this place.

http://www.foxvalleyleather.com/

They're in Salt Lake City and have a downloadable catalogue that includes all types of leathers. TR grade elk for 4.25/ sq. ft and #3 grade for 3.50 (whole hides, sides, and quarters). Buffalo, cow, deer, and more. Tools, knife-making, and black powder supplies.

I love soft-tanned elk.