On an IBR loan repayment program, it wouldn't matter all that much if I had 200k or 400k in student loans (just arbitrary numbers here, 400k is quite exaggerated), my monthly payment would be the same, about 10% of my income. This is subject to change in the event that I did not need to take out a "huge" (whatever that means) amount and/or got a decent job.
For instance, say I take out 200k in student loans and land a job making 60k a year. 10% income = 6k per year in student loan repayment. 10 year IBR = 60k paid (140k I wouldn't have to pay), 25 year = 150k paid (50k I wouldn't have to pay). I'll most likely qualify for a 10 year repayment program.
IBRinfo.org reports that, "IBR and Public Service Loan Forgiveness were passed into law through the College Cost Reduction and Access Act of 2007, and any major changes to these programs would require new legislation to be passed by Congress and signed by the president. This is highly unlikely to occur in the foreseeable future, and we recommend that borrowers proceed with confidence."
So, even though it seems as though borrowing 200k or so for a PsyD is financially irresponsible, it is investing in my own earning potential, and I most likely (assuming a new act of Congress isn't passed) will not have to pay it all back.
So why not go on with it?