If my property's appraised value is more than the purchase price can I use the difference towards my down payment?

The 15-year fixed rate mortgage offers two big advantages for most borrowers:

You own your home in half the time it would take with a traditional 30-year mortgage.
You save more than half the amount of interest of a 30-year mortgage. Lenders usually offer this mortgage at a slightly lower interest rate than with 30-year loans - typically up to .5% lower. It is this lower interest rate added to the shorter loan life that creates real savings for 15-year fixed rate borrowers.