The thought of somebody else paying more or less than you for the same services drives you crazy, then welcome to the real world. Market is driven by supply and demand, and the price of your lesson may have nothing to do with the price of somebody else's lesson in content style or form.
As Fasc said, how he responds when I politely inquire about this new set of circumstances (not just the new rate) will be a good indicator of his motivations for the rate increase. He certainly does not owe me an explanation, but if he is either unable or unwilling to explain the rationale behind his actions, then I can only assume he cares very little that I feel I was treated unfairly. I don't think anyone would take that lightly from any service provider.
And I have no doubt that Larinda would not be offended by me politely asking a question about my new rate increase, esp. if this increase was for me alone. If she is willing to sit down with a student who was angry and upset by a comp bill, then I think she would be more than willing to discuss my new rate with me. I'm still hopeful that my pro will do the same.