M.D.
We paid $10 per day. That was to come over once a day, whatever time was best for them - that is, not at a particular time each day, just once a day. That was possible because we have an automatic feeder, so the timing didn't matter, as long as the feeder was refilled daily. They did also scoop the litter. I don't see that as affecting the price since it takes about 1 minute.
ETA: In my case, it was the next door neighbor, so no driving expenses. She just walked across the lawn. If the person has to drive to you, that's a bigger hassle and I would expect to pay more.