I come from a finance background and I got into SAIS with a 12k/year scholarship. I also got into the other main IR programs and got a significant scholarship from one of them, zilch from the other two. I decided not to pursue an MBA because it didn't really fit my academic interests, and it was the cheaper option. However, many of the international development jobs I want prefer to hire MBAs.
The sad truth is that IR schools are a bad investment for almost everyone. Paying 6 figures and not working for two years to graduate with a $50-80k salary is very hard to justify.
I am doing this because I want to pivot to a career that I find rewarding and to learn about the subjects I find interesting. That to me is worth the investment, but I can also afford to pay for school without taking on debt, which was a big part of my decision.