The quality of the experience you give your child really has v little to do with whether school is private or state, but it does help if it is a good school. IME private schools can blow you away or they can be utterly crap and a waste of good money. And you know what... State schools can be as good... In some cases better. I have a friend who took her younger dcs out of prep and put them into her local primary. She was dreading it, but was amazed... Guess what... They enjoyed it (!) and academic output was the same. "There's NO difference," she told me, clearly still barely believing it herself.
If we lived in the same carchment area, I'd do the same. Not that DS's prep school isn't fantastic, it is. But I know that the state school in question is also great. And free.
It doesn't matter who you are or how much you earn, paying fees is only worth it if the school in question is the best decision for your dc and your family. Sacrifice is all very well for private education and nowadays most people have to sacrifice something (holidays, cars, dream job, more family time... possibly their soul, reading some posts... [bugrin]) but if the balance between sacrifice and benefit is not right, then it might be time to consider other options. There might be better options out there than you think.
On the other hand, if you can scrape by (whatever this entails for your situation because 'sacrifice' is relative) and your DC is doing well, then well done you and buck the fegrudgers! [bugrin]
Do whatever is right for YOU and YOUR family!!!