when we were using the film, we went to FoodSource. They charge $3.99 for double prints any size. Now I have digital.
For those who use digital, you can go to
http:www.winkflash.com/promos/84xz93df enter the coupon code 84xz93df and get 50 free prints 4x6. They charge 99c for shipping, and their 4x6 prints are only 12c each. I used this a few weeks ago, not sure if it's still not expired.