I never pay for pictures. There are so many offers out there for free prints, you just have to find them.
Here's a current listing. If you know of more, let me know!
Kodak Gallery - 50 free 4x6 prints for new members, just pay shipping
Snapfish - 50 free 4x6 prints for new members, just pay shipping
SeeHere by FujiFilm - 100 free 4x6 prints for new members with the code prints, just pay shipping.
Horray - 30 free prints for new members plus 20 free prints every month, just pay shipping.
Canvas People - Free 8x10 Canvas. Just pay $14.95 shipping.