That's exactly what I was thinking. If you play this smart, it could work to your advantage.
Everybody knows gas prices are going up and every single customer you have realizes it hits you in the wallet. What they don't realize is how much (or little) it does hit you.
Let's say you maintain a lawn for $150/month. Do you really use more than a gallon every visit? This of course does not include travel but our routes are laid out very efficient, right?
Alright, after a while you raise his price $10/month. He understands because he has a car, too. Now if gas was $2.50 when you signed him on and now it's $3.50, you just lost $4.00 dollars a month in extra gas costs. Remember you raised his price $10/month. Now when gas prices slide back down, I don't know about you but I never drop my prices back down.
I know this is huge generalities, but if you work it right, you could come out ahead on this.