If you want to borrow $350k at 6.2%, a 30yr loan is $2,143 /mo, and you'll pay $421k in interest over the 30 years. A 50yr loan is $1,894/mo, and you'll pay $786k. So $250/mo less, and $365k more interest, which is more than the mortgage. Yes, 50yr mortgages would be a scam.
7 months ago