Generally licensing fees are payed in one lump sum to Microsoft or Sony. The cost of those fees vary depending on the game and are included in the deveploment cost.
Some games may have different agreements that are dependent on the number of units sold but those are usually killer aps like Halo and GTA that everyone knows will rake in the dough.
You can compare this to the music idustry, the people that record the CD and produce it spend an amount and the publisher spends a different amount but when they talk about how much it costs to make they include both amounts so that the number looks bigger.
I'm not denying the fact that it costs alot of money to develop a game, however, I think there is a misunderstanding about what dev totals include which could be caused by either the media's inflation of the numbers of the developers, because as the OP pointed out the numbers don't add up.
