The "helpers" in the teams are paid quite well these days. Not like pro football players. But they earn a decent living. The prize money of the Tour must more be seen as a bonus for the team, it is split with every one in the team, including the bike repair guy, the bus driver, etc...
Because of the global scale of this event, sponsors pay huge amounts of money to riders, for just being in the break away. The visibility of the sponsor is immense at such times, so believe me they get their fair share!