Diversity is good, and with your medical qualification, you are a rare breed for any top ranked business school. Suffice to say that so long as you have a convincing story for the admissions committee, you should do well in the selection process.
The key is that you don't necessarily have to convince them about a career change from the medical profession altogether. You may just as well be seeking a change from a doctor's role to one of managing medical facilities or even a consultant in the healthcare space. Besides, in case you so choose, there are specialist courses available at certain universities like Duke.
I don't see any merit in doing any finance course especially if you want it to enhance your prospects of admission and/or a job. What I would suggest though is to take a crash course in basic accounting and another in statistics from a tutor who would typically be teaching 11th and 12th grade students. And yes, these will cost you far less than 25,000 all put together.
Hope this helps.