How much does it costs to go to law school- after your all done?

It depends on the school. Some state schools have tuition as low as $5,000/year. With books but no living expenses (eg living with parents, no car), a person could complete law school for as little as $20,000.
However, most law schools are closer to $20,000-30,000 per year, and most students must also factor in living expenses for those years. Some students are lucky enough to have their parents fund a portion of their education, but the majority end up taking out student loans to cover it. Therefore, most people come out of law school with student loan debt in excess of $100,000.