Grooming fees vary according to size & the amount of work involved.
For example, a puppy needs to be eased into the grooming environment, also a dog that visits regularly every 4 to 6 weeks as a pose to a dog that only comes every 8 or more weeks apart.
A dog that visits every 4 to 6 weeks is going to be easier to groom and more enjoyable for the dog, than a dog that has a matted coat and hasn’t been groomed for longer time period. (ie more than 8weeks).
More time will be needed and the cost may increase.
When grooming your dog on a regular basis they are free from most matts and tightening of the coat/skin, this makes more comfortable for them between grooms, I would recommend coming every 4/6 weeks
If a dog comes every 8 to 12 weeks this can cause stress to the dog as their knots have increased over time - especially under the armpits and belly area, between toes and their face hair grows quickly, so they are unable to see clearly.