I think one thing to consider is the average starting salary for students from each law school. I don't know about Tulane's numbers, but as a higher-ranked school than LSU or Loyola, there's a possibility that their graduates get jobs at better firms and make better initial salaries. I completely disagree with the earlier poster who said you should go to the cheapest school. Sometimes the more expensive school also has a much higher starting salary for its graduates, which means that you'll be able to pay off those loans within a few years and be making a lot more money than you would have if you had gone to a cheaper school.
But like JE said, this may not be as big an issue if you aren't going to one of the top 15 law schools in the country. But still, you may want to do some research into average starting salaries.