Those of you that have been to the Canyon lately have seen some changes. The most recent and very expensive is the Bright Angel Trailhead. The Park's budget was nowhere close to the cost of all the upgrades and many of us sent in our donations for the improvement. Neither the Park nor the Association can afford to pay the ever increasing costs of the day to day operations, so some of those who take advantage(read that as use and appreciate) of the improvements and hike the Canyon are being asked to help.
I equate it to the old fee schedule charged at Disney Land when I was a kid. There was an entry fee at the gate and "A" thru "E" tickets with graduated costs. The NPS knows not all of you will hike the canyon and have chosen to ask those that do to add a little extra and they will maintain and improve the trail system. The alternative is a substantial increase in entry fees for everyone.
My wife and I have been to all but seven of the National Parks since we were married and I don't feel that the entrance fees have increased as dramatically as most commodities, especially considering that we get a lot more for our money that Mr. Disney can provide at his parks.
Just my belief.