Roy, it's that way all over as hobby shops only stock what they know they can sell.
If you have a boat club in the area, see if they go in on big fuel orders as I've gotten in on those before.
Finding 50% will be easier than finding nitro over that as there is this Homeland Security paranoia. I'm kind of glad that I bought some 65% before the price shot up last year at about half the going price now.
I don't know off-hand where you're at in Illinois. The northern part I'd try Al's Hobby Shop but in the southern part you can go directly to Wildcat and order from them.
With the expense now with fuel, glow plugs and nitro engines it's no wonder that people are getting into the "weedies".