Charles does this type of thing quite openly. If you are going to write a big check to one of his charities, you get invited to a dinner party at High Grove or Clarence House.
This is not unusual with charity fund-raising, I understand. And it's perfectly fine IMO. It's only a problem if the object is for wealthy business people to buy access to influential individuals who can help them make even more money and the profits from the membership fee or ticket price all go into the facilitator's pocket instead of to a charity.
That's kind of what they are doing when they make those checks. It's not because they are altruists. They write the check, get invited, get access to other influential people and the circle jerk continues.