I was asked by one of my friends to have a look at this thread and encouraged to respond... I don't know if I have anything to add to the debate, but I will give it my best shot.
I think someone of Yahara Sensei and Isaka Sensei's case (which I presume we are talking about, although for some reason don't mention directly) I think they do deserve the fee of US$500 per day. That is also what Kagawa Sensei charges. Plus I think it is right to pay for their travel days.. Let me explain why. I teach professionally, I am in Norway as I write this, having taught for the last two days and will teach tonight in Oslo and then up to Trondheim for the weekend. I left Dublin on Wednesday and will get back Monday morning. Whilst I am away I must pay someone to teach my classes at my full time dojo. Fortunately, including myself, there are four full time instructors at my dojo, so I can always get someone to cover my classes. However, they, like me, are professionals so they must be paid. In this case I am travelling and teaching on the same day (Wednesday) and I get back on Monday in time to teach. So I don't have to charge for a travel day. However, if I travel farther afield I must charge for travel days. I have just taught in New Jersey, USA and Rio de Janeiro, Brazil. Whilst I am away I must pay other instructors to teach, therefore, I must charge the people who have invited me for every day I am out of Ireland.
Of course, my fees aren't nearly as high as Kagawa Sensei
But I know he is in the same position. He teaches twice a week at the Hombu Dojo in Tokyo, but on top of that he also teaches at Teikyo University, the JKF, the Defence Force and various other private dojos through the week... This is where he gets his monthly salary from. I presume Yahara Sensei and Isaka Sensei are the same... So charging for travel days are justifiable, I think.
Now, does this breed arrogance? I don't think US$500 is a lot. Compare this to other athletes of similar level in other sports (I am not saying karate is a sport
) I have trained along side Kagawa Sensei enough on the instructors course to see how much effort he puts in to reach the level he has attained... He deserves every cent of the salary. I think what breed arrogance more is how instructors are treated when the come away to teach. People can not complain about how they are treated if this has been preceded by years of sycophantic behaviour. You can’t complain that instructors think they are Gods if they have been worshiped by inviting students.
Kagawa sensei comes to the UK every year. He teaches good, different classes every time he comes. After training he comes to the bar and has a drink with all the students. Anyone can ask him questions and believe me they do – on these course I spend most of my time translating for him as a steady stream of students come to ask questions. He is never arrogant, aloof or uses his grade as a carapace of protection… He is very amenable.
So I believe that if you are hosting a Sensei who comes, teaches badly, treats students badly and behaves badly, don’t invite them back! It is insanity to do the same thing every time but expect different results