I think a trailer load would let you be a dealer in areas not served by others (or if you can be a better dealer than the one they got). Buying lesser quantities is going to run the freight cost up.....and cut into margins if doing anything less. I would think there should be 25% margins......but I have no first hand knowledge. Often the best margins come from buying 1. Quantity 2. Pre -season orders 3. Buying accessories 4 Payment terms and more.
Thus the discounts may be 20% less 5% less 5% less 3% or some such scheme by purchasing the way that allows the factory to make some bucks too.....and even-out their production.
My 2 cents.
I think one of the biggest things to overcome is the freight costs on big hollow boxes.