Food, drink etc at Permanence and at the road food stops are all paid for by tickets with a varying Euro face value. You buy them in sheets at the Permanence or at the stops. It seems to me like an excellent method of not having to worry about piles of money accumulating for the organisers and speeds things up for the participants as you are not queuing while people fart about counting out small change one way or the other.
They did run out of beer at the Permanence last year right enough.

