Indeed. I think it should be $1250 minimum, which would be a week's pay at a $65000 salary.
I think they might have kept it below $600 because of the IRS's $600 threshold* which to me is tantamount to them deciding not to pay a real bug bounty.
That is still low because of the unpredictability. It might take weeks of work across many sites to find a bug. So the bounty needs to be high to compensate for that, if it is to be a career.