To buy your dream home you need a mortgage for $$275,000.$ The current market rate on thirty year, fixed$-$rate mortgages is $7\mathrm{.}5$ percent. This produces a monthly payment that you cannot afford. The seller offers to buy down the interest rate to $4$ percent, $5$ percent, and $6$ percent, respectively, for the first three years. To accomplish this, what amount must the seller pay up front?