My Kindle is full of freebies. I bought one book (on sale for $2.99 and has since been offered for free) to see if my son would be interested in reading on a device (he's never looked at it) and I bought one book by accident for $9.99 and decided to keep it. The rest of my Kindle books are freebies; if I want to buy a book, I get it from the Sony store or elsewhere.
As I don't consider Kindle books part of my collection -- I don't back them up and I "repurchase" (in epub) the ones that I do want to save. Of those that I backup and maintain, I would say that I have purchased at least 75% of them, and 75% of *that* set are from the store that sold me my Reader (Sony). I spend about $8 - $15 per book, although I do watch for sales and promotions and try to get them for less.
If I'm going to read a book Right Now, then I'm less picky about price -- there is not much that is worse than paying for a book and having it go cheap or free before you even open it but it is worth the enjoyment to me to have paid the extra if I actually read it! However, my backlog is high enough that I nearly always wait for the reduced price.
I spend more on books now than I did before I got my Reader. Space and storage has always been an issue in our house and the main reason I held back from buying more. With my ebook Reader, I'm spending less money per book but making up for it in quantity.
