I did fairly well last month. Two books bought from Amazon (one a reference book ON SALE, and one a collection in a favourite series), and one Baen Bundle that had two books in it I really wanted, and two others that I might read. (And two that I'll never read.
) The bundles are $18 USD, so that's an average of $3.00/book, but really, no better than $4.50/book I might actually read. Overall, I'm reasonably pleased, though I might have been a bit more patient on that one favourite series and gotten it from the library by the end of the summer.