Calculation

I’m a RE broker.  I have a form on my website that allows people to get auto quotes on commission.  If they enter 100k as a sales price, it will email them my commission for that price.  What I want is to set a minimum commission in the equation so if anyone enters a home value of 85k or less.  I want my commission to be $1700.  Is this possible?  

Right now its just Home Value x % commission = Total Commission..