My kids go to private Lutheran schools. My son is still in k-8 (7th grade). We pay $4k per year for him, very reasonable for us. My daughter is a senior at a Lutheran HS, tuition is 12K per year NOT reasonable. We make too much to qualify for vouchers. She really wanted to got there and earned an academic scholarship for all 4 years bringing our bill down to about 8k. We started a College Choice 529 education savings plan for college when she was born. Indiana changed the law about 5 years ago so that you can use those dollars for K-12 private schools. That allowed us to manage sending her there. She is third in her class. The two kids ahead of her are going to MIT and West Point (her HS has an outstanding JROTC program). She earned a full ride to Concordia Chicago to be a Lutheran Teacher. The two aformentioned students are both voucher students who would have never gotten into this HS without them.
Is the voucher/529 plans perfect? No, but it opens door for those who might not be able to otherwise. Indiana moved last year to increase income voucher eligibilty from $72K (Family of 4) to $140K starting next year, this voucher will cover up $7K per student.