They will make money on the interest rate alone. You do not need to pay them their costs to make more money off of your situation. Remember, the person you are dealing with is NOT a banker or loan officer. It is very possible that when you say you want a better deal or you will not pay for certain costs, they will not know what to do. You are the exception in negotiating your deal.
Most people act like sheep, accepting whatever they hear.
So, the loan salesperson you see sitting in front of you will have to talk with their supervisor. That is not bad for you. Stick to your guns. It is your pocket that the money comes from. You will often hear that interest rates will be going up.