Now that I have a device which can read eReader format again (my preferred format for 'new' books as it is not, like mobipocket, tied to a specific device or number of devices, but is reasonably eternal) I have been buying new e-books again. I love it, and find it makes real economic sense for me. In the absence of this option, what I was doing was buying used books from the used bookstore, reading them and then selling them back for maybe a dollar or two because I simply don't have the space to keep them all. Sometimes, I would come to regret purging a certain book---I recently started re-reading a series I have, and some of the books were missing

I do read a lot from the library. But if it is something like a mass-market paperback, or if it is a book I may want to read again, I like to own it. And Fictionwise has some good deals wit the micropay rebates where you can get free books!
Anyway, just for fun, I plugged into Google Docs a tally of all the money I have spent so far on both devices (not counting multifunction ones like my PC and iPod Touch, but counting the ones I specifically bought to read on) AND my Fictionwise spending to date. I added up this sum and divided it by the number of books (free and otherwise) I have read so far to get an approximate 'cost per book.' And my result?
It was $6.25 until the micropay sale I just binged on. It is now $7.42 which is STILL cheaper than if I had bought all those books (which I would not have been able to keep) in P. And if I actually finish every single book currently loaded onto my ipod (assuming I spend no more money in the interim) it will go down to $2 a book. I know the internet freebies lower the average

But I am counting everything I spend and every book I read.
Not bad!