You don't have to pay for a photo with Creative Commons License.
The Creative Commons (CC) is a non-profit organization devoted to expanding the range of creative works available for others to build upon legally and to share. The organization has released several copyright licenses known as Creative Commons licenses. These licenses, depending on the one chosen, restrict only certain rights (or none) of the work instead of traditional copyright, which is more restrictive.
Most of the time, you simply have to mention the name of the artist. Creative commons licensing is on many things including documents and photos. Artists share their works so they can build on a piece and "Create Commonly."
There are some crazy things going on in this world. Barry Bonds might play baseball for absolutely nothing. He just wants a team to pick him up and he'll give his paycheck to charity.
A guy is giving money away to anyone who wants it. You have to do a song and dance, but you can ask for any amount for any reason. Now, that's crazy.
Creative Common License is not crazy. Plenty of artists love to see what happens to the work they started. Collaboration, sharing...that's what the internet is all about. So, if you need a photo for a brochure or a book you're writing, take yourself on over to Ninjaphoto and see if there's something you can use.