i am not intimately familiar with any of the schools above, but I have lived in Nashville for a year and for few in NC. Vandy has a great medicine program. the companies and hospitals around Nashville along with this program give Vandy great advantage if you are looking to go into that sector after business school. but, also bear in mind that there will be many others at Owen who will have the exact same thing on their mind.
kenan-flagler is ranked well above Owen for a reason, the facility, student quality, professors, research is top notch. recruitment at the school is testament of that fact.
if you can, do make a trip to Nashville and Chapel Hill. Visit the campuses, sit in a class, talk to alumni.
its not about $$, its your life. the $$ difference can be made up in few short years.