Seems like it could be even easier than that: create a smart phone platform where season ticket holder has a sliding switch (like you use to turn Airplane Mode off or on) for each game. You could even have options at the top to make all tickets available for resell, midweek games only, etc. As long as it's in the "on" position, the ticket could be resold by the University at the walk-up ticket window. You could go a few routes on the revenue made but 2 options are:
1) Athletic Dept keeps 100% of resold ticket revenue and ticket holder gets a credit towards Bulldog Club donation credit at the end of the season for all revenue generated by the resold tickets. Essentially the athletic department sold the same ticket twice and only had to provide points which have no cash value. Could even have different prices for tickets like $6 for behind plate, $5 other lower level and $4 for upper deck.
2) Athletic Dept and ticketholder share a percentage like 60/40. Keep in mind that this really only makes sense for athletic department if they're making more than they would for a GA ticket.
Just a thought but it seems like this platform would work for other universities if someone created it, and you could also get a % of each ticket sold.