I run the calculations for you here, because I think they are interesting:
Private medical school $40,000 per year times 4 years. At the end of four years you will owe about 185,000 with the accrued interest, assuming a 6% rate. Now the interest continues to accrue during your residency, lets assume a four year OB/GYN residency. This now puts you at $234,000 This is the amount of money you have to pay back.
Lets assume you take a high paying job and can afford a ten year repayment schedule at a conservative 6 percent. Amortizing, this equates to a monthy payment of $2840. Multiply that time 120 months and you get: $341,000, Thus, it take $341,000 to pay back $160,000.
Now here's the good part. You pay your loans back in after-tax dollars. Since you are a physician and have a "high" income, you do not qualify for the interest deduction on your student loans. Also, since you have a "high" income, you will pay an effective tax rate of 40-50% factoring in federal, state, local, FICA and Medicare taxes. In other words, you have to earn $1.60 - $2.00 to pay off each $1.00. In total, then, you have to earn between 545,00 - 680,000 to pay off your loans.
Two other things to note. First, this calculation assumed a fairly low interest rate of 6%, that is very unlikely to hold for long. Second, if you really want to assess the financial impact of the two different routes, you should add in the stipend you get in the program and the differential in residency pay. The stipend probably adds up to $50,000 while the residency differential is about $10,000 - $15,000 per year. This adds up to approximately another 100,000 in benifit to the scholarship.
We my colleges act incredulous that I "sold my soul" to the army, I respond that they sold theirs to debt and I have my soul back 4 years after residency, not 10 or 15 like them.
Hope this helps,
Ed