Like many sports fans across the world, Dortmund fans are upset with increasing ticket prices at sporting events. Unlike many sports fans, they decided to voice their displeasure by throwing tennis balls on the field in the middle of the team's Bundesliga match against VfB Stuttgart.
According to The 42, Dortmund supporters have to pay €19.50 ($22.02 USD) for standing-room tickets and €38.50 ($43.48 USD) for the cheapest reserved seats. Visiting fans are paying as much as €70 ($79.05 USD).
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Dortmund led the Bundesliga in attendance last season with an average of 80,463 per match.