We live in Surrey and my son is at a prep school just over the county in Berkshire, 20 minutes drive from us. We pay £600 a month, £7,200 a year and that includes lunches, school-led extra curricular, before and after school care from 6-8 and all holiday care. In terms of cost it feels like halfway between an independent and state school but in terms of educational experience, it feels more like an independent.
We’ve been there since September (my son is in preps/juniors), it’s small, nurturing with good discipline and small class sizes, max 21 in a class and experienced teachers. He’s getting on so much better than at his previous state school although my older children did fine at state school, it was really that my youngest was a bit easily-led and he benefits from experienced teachers and better discipline - he’s academically reasonably capable.
The school does not have fabulous grounds or brilliant sports facilities, but they have use of a local boarding school pool and Forest school facilities, they learn three languages and have all the wider extra curricular opportunities, art/pottery/cookery etc plus preparation for the local grammars (because many children don’t go on to private secondary).
I think state v private really depends on both the child and the school, as I said, my other children did well at their state primary and have gone to state secondary with no issues.