The Hardwood Store of NC shows basswood 4/4 @ 2.85, 8/4 @3.60, 16/4 @ 5.60. I saved this site to my favorites about a month ago so I don't know how current that is wood prices change about like the stock market. This was for 1-99 board feet. The price goes down some for higher quantities.
Wow! You need to find a sawmill if there are any in their area. I would think you could find the 4/4 rough basswood from 45-60 cents/bdf depending on width. They may even cut it thinner for you if you're not in a hurry.