I just paid $77 for Kelly Rae Roberts set of three e-books about learning to fly creatively. I don't buy online often but she was running a half off deal. I guess I really skewed the average.
I only paid that price once, and it was for a book I'd been waiting a year on. When push came to shove and there were several out that the publishers were wanting 9.99+ for the e-book (one was 12.99), I said screw it. I joined Rhapsody Book Club and got them a LOT cheaper. Yeah, I ended up getting physical books, but they got read just the same.
I prefer e-books because (much of the time) they cost less and I can carry hundreds with me at once. If you read like I do (a Harlequin Presents - yes, I read romance primarily - takes me under an hour), there is a huge value to carrying multiple books around at once. Best of all, I can read them on my phone, my nook, or my husband's iPad.
Actually...if i am going to pay any money - i will spend it on a real book. So, the most i have paid for a book is nothing! Too bad that wasn't one of the choices