Here is the link for the STP tuition and room/board http://www.vmi.edu/academics/summer-programs/summer-transition/fees/
Although STP is a great way to get acclimated to the VMI environment, another alternative is to take a class or two at a local community college to lighten your academic load during the Rat line. It is very easy to obtain permission for transfer credit from VMI admissions prior to matriculation. Whether you attend STP or a local college, one class I suggest you get out of the way is World History.