I , also , agree-volume discounts do more than "make no sense" they also can be like an AFB arrangement. Which might include you as a co-conspirator also.
By offering "volume discounts" one opens up that client to a potential "kickback" charge or a section 8 violation.
Volume discounts can be discouraged just with that kind of explanation- I have never been asked to get involved with that kind of activity- probably because the clients I have dealt with recognize that pitfall. The fact that each transaction is a separate deal- separate settlement and HUD-1- there is no reason to think that the customer is actually benefiting from any so called  "discount" , rather it is the VMC that is taking the discount - or "kickback" in its true form.
Just say 'NO' to any request for discounts-they are not part of our business or should they be with our clients either-they should not even be asking that kind of question of us-knowing the ramifications of doing so.
Steve Meinecke

Franklin, TN