That's hard to answer on a year-by year basis. An unemployed person may not go at all, or only be willing to go for $25 bucks or less. That same person fully employed may pay 2 or 3 times as much. I agree though that the prices are far too high.
Worse yet, ticket prices have also outstripped inflation by a huge margin in the last few years. When Notre Dame made their first NCAA in 2004, my ticket to Van Andel cost $20 per session when bought as a 2 day package. By 2009 that same ticket was $32.50. That's an increase of 62.5% in just 5 years. Had the cost gone up by the same amount as the CPI the ticket would have cost $22.53. In 2012 it would be just $24.10. Now of course more goes into the cost of any item than just inflation, but the point is still valid.
As a price point target, I'd say the 3 game all session ticket should be no more than $50 and a single day ticket should be no more than $30. And I'd go further and say that would be a target for a ticket with an anticipation of selling well, like this year in StP. Notre Dame was charging as much as $90 for a full session ticket in 2010 and that was obscene. It was greedy. It was also why no one was there, even with Miami and Michigan being easy drives.