Hi Lam, The old edicate you are mentioning was once the way of things. But time, greed and a general evolution of the hobby has kinda changed all of that. In fact, in the old days, customers would bring breeders gifts in order to be treated well and as a sign of friendship. O how I long for those days. But they are gone now and koi is big business. And a hobbyist bringing a gift ( other than a token) and bowing like a duck is like putting a sign on that says " I don't know what I'm doing, please take all my yen as quickly and as boldly as possible"
Many things are misinterpreted by the first time hobbyist-buyer when arriving in Japan. One is that your dealer is YOUR advocate. Usually, your dealer is more of a sales representative for the breeder than your ally. They can advise you, help you, make the transportation of the fish home for you an absolute breeze, etc. But they are there primarily to have you buy koi from the breeders they take you to. And they have a relationship with that breeder and often are also buying their company's or shop's fish from the same guy- year after year. They are also often given a undisclosed percentage on every fish you are buying, Often this is a credit against fish that the dealer will buy for his own inventory. So that relationship is more important than the relationship with any one customer- especially one that is just passing thru the hobby or taking one, and only one, trip to Japan. So it is wholly unrealistic to think the dealer is your 'man on the inside'.
One of the most blatant attempted screwings I experienced was from the son of a well known Hiroshima breeder. He offered me a tosai male tateshita. It was a very nice finished show fish so I was interested in it as a 'fun fish for a koi show'. I was thinking maybe $500- 1000. He then gave me a price------ $7500!!!!! For a finished two year old male fish with a zero future but a good fish for winning baby champion or best of size 2 --- maybe! I flipped as I tend not to take insults well. It was only then that my dealer pulled the little shite over to the side and discussed the price. The price dropped $5000 in an instant. In that case, the dealer did the right thing for his customer. JR