This is a very narrow concept of efficiency. The person who drops $500 on a ticket doesn't necessarily like the band more than the person who can only afford $50. People are always citing models of price efficiency forgetting that perfect competition only obtains under very limited conditions, and that participants are theoretically free to enter or exit the market at any time.

Bands don't generally want to maximize revenue from any given gig, they want to maximize fan loyalty because it's the dedicated fans who spend the most money over the long term. Overly simplistic pricing models don't account for this. In economics your aim is to maximize utility. Money is only a proxy for this, and often an inaccurate one.