Good news for self-publishers. Create Space has extended their Free Upgrade to Create Space Pro until the end of the year. The upgrade normally costs $39.00 per year, per book. In return for the additional fee, the publisher gets a lower wholesale cost. For instance, a 200 page book with a black and white interior cost $5.50 under the standard plan but only $3.25 with the Pro upgrade.
You need to sell around 20 books to pay for the $39.00 Pro upgrade – then all other sales will net you an extra $2.25.
Of course, since the Pro upgrade is free – it just costs less to print any book. Note however, that you do need to actually go though the steps of buying the Upgrade before printing your book. It is not automatic.