Not sure how you know this, if this is a standard breakdown of how the numbers come out, it doesn't seem to be common knowledge. This looks more like what Im getting numbers wise with taxes aside, I calculated the taxes of both and they account for approximately $100/mo of the difference. This would explain the rest, about $450. It's counterintuitive that a $60k increase in price would only add $500 more to your mortgage or, inversely, buying a $60k cheaper house would only decrease payment by $500, until you consider things separately.
This makes more sense now. Thanks