Has any price guide ever appeared for chips from the Mid-states area? I know one was hinted at many years ago. I have a box full and don't know what to do about trades and pricing.

I don't want to ask too much and rip someone off, and of course I don't want to trade them off at face and find out they were of higher value. Most of the $2.50s are gone to happy homes, but what about the others?