Mezzanine tickets to hockey games at the St. Louis Arena are $20. When the Montreal Canadiens come

Question:

Mezzanine tickets to hockey games at the St. Louis Arena are $20. When the Montreal Canadiens come to St. Louis, the game usually sells out. Scalpers get as much as $50 a ticket. Most people at the game, including many who paid scalper prices, end up with consumer surplus. Explain.