The buy rate is the rate that gives the Agent zero commission on an ACH loan. It's up to the Agent to add the amount of commission he thinks he can sell to the buy rate up to the maximum that each lender allows (usually 10-12 points on funded amount). Think of it in terms of the auto industry. The buy rate is the dealer invoice price and it's up to the salesman to sell the car anywhere from the dealer invoice up to the MSRP (or maximum allowed price). The salesman's commission is based on the spread. It's up to the Agent to try and maximize his spread between the buy rate and the rate the yields the highest commission.