A great way to get free or cheap prints is to sign up for email lists!
For example, the other day I signed up for Snapfish.com‘s emails, and they have a special running right now:
“Hurry! You have 2 more days to order 99 – 4″ x 6″ prints for just 99 cents! At only a penny a piece, you can share more of your summer fun for less. Use couponJULY99PENNY at checkout.*
Don't wait – the extension to this limited offer ends July 13!”