My son is in private primary. He’s an only child and we were fortunate that money is not an issue for us.
The state primaries near us are not outstanding but perfectly fine. However the state secondary options are not good at all.
Therefore, it’s really common for people to do state primary and private secondary. However the best private school in our area offers “straight through” from Reception to Sixth Form, so we thought it was worth a punt, because if he got in at age 4 then that meant no stress doing 7+ or 11+ exams, which has seemed utterly utterly miserable for friends and acquaintances.
We were lucky, he got in (we did not tutor or prepare him in any way, nor did we send him to a nursery that was a feeder to the school).
He is happy and thriving and I do think the small class size has been better for him than 30 in state. As a pp said, the uniform and extra curricular stuff is actually not expensive at all, including after school club that makes it much easier to manage our lives around work. It’s easy for me to say, as we’re in, but I do feel that the foundations of learning that he is acquiring now will stand him in great stead for his time at senior school. He may well have got those in state primary too though- teaching methods have moved on massively since I was a child, I’m sure. (And it IS important to remember that using one’s own experience as a point of reference is not really a helpful way to go about choosing a school 20 or so years later).
Therefore, if you are aiming for a happy stress-free childhood for your child (who isn’t?!) then you might consider either a straight through private or just sticking with state all the way through. I feel that the entrance exams are quite a toxic thing.
On a separate note, you said if Labour do impose VAT then it is a dealbreaker. My understanding is that it is very likely Labour will win and very likely that they will tax private education more heavily so you really have to take this seriously.
That said, our school is already consulting with parents about how to deal with this and they are not assuming that the full 20% will be passed straight on. That does mean, however, that they are looking at cutting back some of what they offer, as they will be able to provide less for what is being paid.