First off, I completely agree with the asking fans for money. As a music lover, I see it everywhere, and encourage it. I love it. Music is getting more personal, more intimate. The era of the minstril is returning. I fully support everything you do in these matters. That being said, the rest is a devil's advocate position, with the intention of helping you gather information to perfect the new model, if the information is needed.
The auctions bothered me, and it took me a while to figure out why. Eventually I realized I just didn't like the idea of people paying THAT much money for those things. That crosses a line in my book (a line in that I would question their priorities). Yes, that's a judgment, and yes, people can do what they want with their money. They weren't forced. This is a purely personal tastes thing, and once I realized that I forgot about any hangups.
But.
Putting the auctions in terms of the rest of the blog, this isn't asking every fan for money (a 10-dollar-entry webcast would be that, which I highly encourage you to do). These auctions profit off of the fanatic and not the fan.
This is 10-20 people spending a whole lot of money. And they adore you. They will do things for you and probably not necessarily realize the repercussions. This is not your fault or responsibility (debateable for some people, though that's a moral grey area), but it is what is happening.
Amanda, asking the fans for money its something that is true, and everyone will have to get used to it if they continue to sample an artists content for free. I think you have been extremely astute in predicting this.
In these auctions, specifically, you're profiting off of the fanatics, tapping into (what I percieve as) a personal vulnerability in your fan base, their adoration. Credit where credit is due, you deserve this adoration, I've never seen an artist give so much back.
But, it borders exploitation, despite them doing it willingly. You say that Ticketmaster, Roadrunner, etc have been "shamelessly raping both fan and artist for years". Be careful, these auctions are bordering on comparable.
Do you want to pave the way in new ways to ask the fans for money, or profit from the fanatic?