I don't agree with this statement.
They either have a fiduciary duty toward the members, in which case, if they are allowed to charge a fee, it should be only to cover expenses.
Or they don't, in which case if the law doesn't prohibit it, they can charge whatever they want (even 10K).
But one cannot claim they are acting in the interest of the membership when they stand to gain a couple of millions per year doing this (assuming 500K is more than enough to hire a few CM to handle the transfers)