What are you talking about? Mortgage interest deduction determines how much money a private person pays in taxes to the federal government each year, relative to their income minus deductions. It does not directly impact home sale price.
The National Association of Realtors argues that removing the mortgage interest deduction would reduce home values by 15%. There are likely other less biased studies as well but that was the first that I found during a quick search. More at https://en.wikipedia.org/wiki/Home_mortgage_interest_deducti...