How much should I charge for pet sitting/house sitting?

I am an experienced dog groomer and I own my own grooming business. I want to start expanding into dog sitting/ dog walking/ house sitting. I have no idea what to charge, I am looking through tons of websites and getting anything from 10-20 a visit, or 10-75 a night. I know I need to adjust pricing for dogs who need medication or other special needs, I know it should be more for overnight stays, but I have no idea what to charge. Some small dogs I may just keep here at my house. Gas these days is outrageous, so if I am doing 2 visits a day I feel that should be taken into account. I do have tons of experience with dogs and cats and I did house sit and petsit on the side for friends of the family my whole life. Any suggestions would be greatly appreciated. I live in the Baltimore county , Maryland area.