I’d step back a minute and ask why the interest in law? Assuming your kid is going to go to college whether or not he goes to law school, then we are just talking about the cost of law school both in direct costs (tuition, room, board, expenses) and the opportunity cost of 3 years out of the workforce. Of course if college is in question, then you should look at the cost/return of likely colleges, but I would look at each separately. You can look up the cost of attendance at the schools you listed to get a ballpark estimate for both college and law school.
Does your kid have an interest in advocacy? Advocacy is not limited to social matters and can include private business related matters. Or is this interest driven by perception of having a solid good salaried professional career? If the latter, realize that below a certain level of law school, you need to be graduating at the top of the class to ensure even a good local/regional job. Lot’s of horror stories of students graduating with huge debt out of law school and having limited employment prospects.
You mention that test taking is an issue. The LSAT is incredibly important in law school admissions and merit scholarships. After that, there is the mother of all test, the bar exam. Is law playing to your kid’s strengths is a question that you have to consider.