Unless as a parent you feel that you really aren't academically able to tutor in certain subjects to 11+, I have no idea why anyone pays. My friend pays for her son who is sitting a 7+ test - I mean surely she can teach him 7+ Maths and English!
Frankly, tutoring costs far too much. My other friend's son goes to a weekly class for 1.5 hours where he sits and does tests with 8 other kids and it costs her Â£30. If he is weak in some areas, the tutor then privately tutors them for Â£30 so that's Â£60 per week!
I wish I had a teaching qualification!
If children are being tutored from Year 3 (it does happen) then it's either a sign that they are in an appalling school or they actually shouldn't be at GS if they need such long-term coaching!