A proposal floated by the Trump administration to create a 50-year mortgage product to improve housing affordability could offer significant immediate savings to homebuyers, but at the steep cost of a doubled interest payment burden over the life of the loan, according to a recent analysis by John Lovallo of UBS Securities.

Discover how making extra mortgage payments could save you thousands in interest and help you pay off your home years sooner.

Mortgage rates are easing after the Fed's October cut, but $800,000 loans still come with hefty monthly costs.

At a 6.3% interest rate for a 30-year mortgage, the monthly mortgage payment would be $2,030 in principal and interest. Assuming the same home sale, down payment and interest rate, the monthly payment for a 50-year mortgage would be about $230 less at $1,800 a month.

McClelland said for a 30-year term, the monthly payment is about $2,771. The total interest? Around $547,436. Extend that loan to 50 years and the payment drops by $300 a month. However, the new total interest now, an estimated $912,666.

If you're buying a home in the $750,000 range, recent rate shifts have had a big impact on what's owed each month.

Borrowers could achieve the same monthly payment reduction by securing an interest rate that's just one percentage point lower, which is possible to do with seller credits and other incentives.

If you’re shopping for a $300,000 home, how much you’ll pay each month depends on more than your interest rate.