It wouldn't surprise me. Every other industry is raising costs and the consumer is taking the hit. The Milk industry, Ice Cream is going up, Airfares are on the rise again. I think it may be worth it to increase rates to cover additional cost such as gas. But, I suspect you may also, have to look at your rates and how they compare with others in our industry.
I'm not raising my rates yet but I may have to if gas prices continue to rise.