Finding propane prices on line.

Confession time...Driving down road in a larger city. I spot a place that has propane, coffee and is easy in and out and lots of parking. OK, I know need some propane. One tank empty and I'm thinking probably the other tank is 1/2 or below. I park a ways back, remove tanks out of TT and lug them over to his filling place by the hose. Wife goes inside to get us some coffee, I say fill them up. When guy is done I look at the gallon meter and remember how many gallons. Guy rings up coffee and propane and turns out he sells it for $3.74 a gallon. I usually don't drive around trying save 2 cents a gallon on something but $3.74 a gallon!!!

Anybody know where propane prices are posted on-line, sort of like gasbuddy?