Under state law parents have a legal duty to among other things educate minor children until they graduate from high school or an approved equivalent. The state also provides for public schools which are mostly taxpayer funded (the final two years of my high school education would have cost my parents about $1,500 in unavoidable fees).
Both of my parents signed nine legal documents that spelled out every party's responsibilities ad nauseam. My high school agreed to pay for 50 credit hours at a local college and accept those credits as the complete fulfillment of my high school graduation requirements.
My guess is that the district received some manner of a discount. But were my parents to purchase this it would cost them about $47,000.
My father is trying to abrogate the deal he signed -- so far he hasn't met with success because the paperwork itself clearly states that all of the signatories (me, Mom, Dad, my counselor, and the principal) must agree to and countersign any modification to the agreement.
He states that since I am receiving the benefit, an education valued at about $47,000, and he "could have" satisfied the state's educational requirement in another way (sent me to a parochial school or laugh homeschooled me) the contract(s) he signed are invalid because the fact that he doesn't have to pay required text book fees, technology fees, lab fees, diploma and registration fees doesn't count as "consideration" so it isn't a binding contract.
PS: My father is so smart that he felt no need to have a lawyer review anything before he signed it.