Indeed! However Professor Jesson losses the plot when he argues:
Private schools are not required to follow the national curriculum and are therefore free to coach for grammar school entry tests - one reason why parents choose these schools in the first place," said Prof Jesson. "The contrast with pupils in state primary schools could hardly be sharper. These pupils have, by law, to follow the national curriculum and any coaching would have to take place outside of school and at substantial additional expense."
The latter approach is definitely extremely cheaper than attending a private primary school!