Hi CoolMum 5, I really wouldn't worry about what other parents are doing. My son (yr8) went to an Indie from a state school (with a bursary), so it was a whole new world for us. I have heard that there are boys who have tutors there, but these are the lads who are struggling and perhaps some had a little too much tuition to get in there in the first place.
I thought that my son would be behind to start with as the school obviously has a large intake from prep schools, but this has not proved to be the case. He is doing very well, and is definitely working to his FULL POTENTIAL due to the excellent teaching and curriculum at the school, so it would be rather pointless to have him tutored as well.
I hope your son enjoys his new school as much as mine does.