Petsitter increasing their prices ?

Hi, I'm a owner of a dog and I usually use rover to take care of my dog when I have to go somewhere for few days or when I have an event and too busy to look at my pet. Most of the time, everything go well and I leave a review to the petsitter. I don't put 5 stars a lot cause I feel like perfection does not exist and there are plenty rooms to improve. But I reviewed 2 pet-sitters with 5 stars because they did a great job and they were nice, so I wanted to give them a good rating. However only them have significantly increased their prices after that by more than 100% (like 10€ to 25€) and they did it on every services. I know that quality pays off but why would they increased that much, I'm not living in a rich environment or even close to that. Are there any rules that links between the reviews/rating with the prices they charge ?