While differing prices per game have not been documented, NFL teams have required fans of opposing teams to buy tickets to multiple games if they want to see their team.
The Dallas Cowboys have been known to sell blocks of tickets to opposing fans only if they buy an equal allotment to a preseason game.
Recently, the San Diego Chargers announced a change in their ticket policy for their Dec. 8 home game against the Oakland Raiders, whose fans sometimes account for as much as half the crowd at Qualcomm Stadium.
If fans -- whether their allegience lies with the Chargers or the Raiders -- want to buy tickets in groups of 25 or more for that game, they must also buy an equal amount of tickets to another game.
When individual tickets go on sale on July 27, 2,000 a la carte tickets will be available to the Chargers-Raiders game, said Ken Derrett, the team's vice president and chief marketing officer. After those are gone, fans who want tickets to that game must buy tickets to two other games.
-- Darren Rovell