Payments for Medical Bills. You were in a car accident and have to pay the injured party $20,000 for treatment. You offer to pay them $5,000 a year for 4 years. They agree to spreading your payments...

Payments for Medical Bills. You were in a car accident and have to pay the injured party $20,000 for treatment. You offer to pay them $5,000 a year for 4 years. They agree to spreading your payments over time, but only if you pay $5,200 a year for 4 years. Why did they make this counteroffer?