At our school, if you take the DE through the HS (Gov school), it’s free. If you go through the CC, you have to pay and get the HS to sign off on it. When Older S was in private middle school, the principal had connections with a higher up at the CC who gave him a “scholarship” for his math class. She had a similar connection with the local uni. So those were free except for books. But when he took Intro to business on his own one summer, we had to pay full price for that, roughly $400 for 1 class plus the book.
Edit: You are also either a homeschool/private kid or a public school kid. You can’t just take 1 class at the public school. We ran into that with older S and his math as well. Public school wasn’t an option unless he was enrolled full time.