You may not be aware, but for a little while Paizo has been publishing a good deal of the old, more obscure SF & Fantasy Pulps that influenced early gaming. Authors like C.L. Moore and Michael Moorcock are among those in this series, called "Planet Stories." This is a great series for those who have not read much of the notorious "Appendix N." Some of the fiction here is wonderful campaign fodder. Other stories give a good insight into where our hobby comes from. Either way, many of these are a great price. Some are currently on sale for as little as $3.00 per book! It's a good deal.
If you are interested in them you can buy them here:
Planet Stories Fire Sale