Is there an easy way to compare dealership service costs?

I am moving to Florida from Michigan next week and am getting the rear brake service done up here before I make the drive. I was quoted at $47.50 at a dealership in the middle of the state - so imagine my surprise when I had to pay $92.50 to get it done closer to home! It wouldn't have been worth the hassle to drive up (and in the end probably only save $20), but I didn't think I'd see quite this much difference in price.

Short of calling around, is there any other way to compare the service prices from different dealerships? I know that with moving to a major city in FL my costs will probably be higher anyway.