RTÉ: how much does it spend paying people who appear on its shows?

(Overall I think RTÉ - despite the enormous indefensible waste on ridiculous salaries to muppets like Finucane and Duffy - gives us the best and most informative/educational shows on radio, and after TG4 the most educational tv programmes. It's a world better than TV3 or any of that ineffably tabloid dross. Shudder.)

However, I was talking to a (sound) fella last night and I was telling him that I heard him on the radio the other morning. As the conversation got going he told me that RTÉ pay him when he appears with his "expert" views. He spoke for less than 5 minutes and got @ €100 for it. "What!", I said, and he laughed. He doesn't need the money and would talk for Ireland, but much, much more importantly every time he's on the radio or tv he gets more publicity and his career does even better. So, why is RTÉ paying him in addition to giving him an unparalleled platform to promote his own career for free? Why aren't they charging him?

Now I'm wondering are all those self-promoting shítehawks on the Pat Kenny Show, Morning Ireland, Derek Mooney, Drivetime and all the rest actually paid by RTÉ, rather than paying RTÉ for the unparalleled free publicity?

I could start making a list now of these enormous windbags that repeatedly show up on RTÉ radio and TV, but I'm bound to miss some.

Question: How are these payments justified, and where can we find out how much RTÉ spends paying all of these "commentators" and "experts" for promoting them?