That's a big dollar difference. There is a difference in schools as well as locations. KF is Top 20 and MBS is somewhere below.
I have heard negative experience about trying to recruit for a job in Australia after graduation if you do not have strong WE or PR card. Canada and Australia both value Work Experience over the MBA degree and both do not offer as high of comp/salary as you would expect in the US. That was a few years ago and may have changed in the past few years but it was a big concern for many grads several years ago when Australia was not having the best of times.
At the same time $40K vs. $180K is a big difference and with uncertainty in the US, a much more manageable number even if you have to work for much less. I see your dilemma.
P.S. Consider where you want to be long term. Do you want to live/work in the US or Australia/Asia?
At the same time KF will not be a walk in the park for those graduating and you will need to recruit, network, work your read end off to get a good job. Read some
BSchool Reviews.