Misunderstanding the relationships.
A dealer who runs junkets to Japan is both an advisor and a sales rep. meaning they will advise a customer within certain parameters regarding the sale. And dealers can be paid many different ways- a straight commission, a hidden commission and even credit on inventory against the fish the dealer will buy and bring home. The commissions vary from as low as 15% to as high as 40%. And often the commission can be collected on both sides- 15% from the customer and a 15% discount from the breeder. You must remember that you, as a customer, are a fleeting event. But the business and the relationship between breeder and dealer is an enduring relationship. So at the end of the day, the dealer is a sales rep for that breeder. And it is unrealistic to think that a customer is the first priority. Or that the customer will ever really know the true markup or cc. It's best just to focus on the fish in the bowl and if it is worth the final total cost or not.
Another profit center for instance will be growing costs which a breeder may or may not charge for the first or even second year. The dealer will charge a fee for that service and charge what appears to be a reduced percentage commission charge because he is making it on growing fees.
I have one friend who was paying a breeder directly ( unbeknownst to the dealer) for growing fees after finding that the past growing fees were not being passed onto the breeder from the dealer. The dealer then presented a bill to the customer for owned growing fees and said if the customer did not pay, the breeder would sell his fish! The dealer was a lovely deep beni color when he was told the facts !

JR