If the school is willing to pay for the complete education and it is a goal you want to achieve I always say try again! You need to evaluate why you did poorly the first two times - did you not study enough, did you not study the right material, did you need a tutor to guide you through the process? If business school is going to be free I would highly recommend investing in a good course or tutor to help you.
My advice is to study for knowledge, technique and confidence.
Knowledge means to identify the content that is tested on the exam and understand it from the most basic level and to develop a consistent approach to those types of questions.
Technique means to identify the time saving strategies that will also help you to stay on track and avoid common errors and mistakes due to rushing.
the third element of confidence is often the most important element to test taking - you need to take this test with a positive attitude and know your strengths and limitations so you can take the test in the way that will benefit your score the most.
Becky
Master GMAT Instructor
The Princeton Review
Irvine, CA