The letter said that reindexing occured in 2008 and 2015. From 2009 to 2015 the football team went 32-65 (.330). 2016 to present the team has gone 24-22 (.522). I think you have already enjoyed an increase in quality of your product. Time to pay for that.
I overpaid from 2009-2015, donating anything for a team that has 34% winning percentage is a bad investment. Even at what I donate I think a 50% winning percentage is shaky to think that the quality is justified to raise. For someone who donates 5k a year, this is quite the increase. I believe in Campbell so I will probably suck it up, but if when it starts costing me more money then I expect wins and more of them.
Edit: Especially since I drive 5.5 hours each way and usually stay at a hotel one night in DSM. If the cost goes up and the wins don't, then I would rather save my time and money and cheer for free in my own home