The hierarchy of the Tour
The sponsors pay!!!
The "aristocracy" who have places in the convoy or the village (départ or arrivée) pay, have paid or will pay dearly at some point in their lives.
The middle classes with their camping cars blocking roads and camp-sites probably pay but only in excessive fuel and alcohol consumption. Being mostly foreign they don't pay much of the promotion budget that is included in the daily prices the poor peasants have to pay (or the expenses of France Tele that come out of our tv licence fees).
The peasants who stand patiently at the side of the road waiting for a fridge magnet and a paper hat pay as well but it's all well hidden (and they are not really concerned about the race, that they'll watch on tele, 20 mins after the news and weather; it's all about the show for them, the real fans of the Tour).
When you think about it there are actually precious few who watch the Tour who are greatly concerned about whether the riders are doped or not. The riders are actually following an almost Pavlovian reflex to win prizes and the public watch the show created by them doing it.
Call me a cynic if you like but to find the real fans of pro cycling you need to be at Paris-Roubaix, San Sebastian, or Milan-San Remo (or the Ardennes etc.), not the TdF or probably the other Grand Tours.