Harry and Sally have been house hunting. The real estate agent is trying to convince them that they should buy as much house as they can possibly afford. They are in a 33% tax bracket, so he has assured them that spending $28,000 a year on mortgage payments will reduce their taxes by $9,240. They may be even more reduced in the future, as they continue to rack up the big raises over the next few years. The couple has always used the standard deduction and isn't really sure how the itemizing thing really works. Sally vaguely remembers her tax professor in college warning the class that some real estate agents tend to oversell the tax benefits of home ownership. What factors would cause the actual tax savings of a $28,000 mortgage payment to be less than the payment times the couple's highest MTR?