The banking and lending industry is one of the most profitable industries in the world for the lender, not the borrower. If you buy a home and take out a 30-year home martgage loan for $500,000 at an APR of 4.5%, your monthly principal + interest payment will be $2,533, every month for 30 years, or untill you sell your home. assuming you stay in your home for 30 years, how much total money will have paid the bank in 30 years?