Who says you have to follow the school's curriculum. Send your 2nd grader to Kumon Math. It's relatively affordable and your child will be out achieving the other kids in no time.
My school district is a pretty well regarded one in my state. I also contribute over $7,500 yearly in property taxes to fund this district. "Relatively" affordable is a complex idea as far as I see it.
How does the amount of property taxes you pay matter? It seems to me that it's your responsibility to see that your child gets a good education. The school is just a vehicle for that. If something is lacking then you have 2 choices: work with the school to fix things or supplement your child's education out of pocket. Kumon costs around $100/month/kid. You can judge for yourself whether that's affordable. Btw, many of the kids at my children's Kumon Center had teachers as parents. While it may feel nobler to battle the bureaucracy and to try to get your $7500 worth, your kid will likely have graduated long before you can effect any change.