I don't know what their printing rates are, but it doesn't really matter. You shouldn't print and delete your pics - the files on your memory cards aer your negatives, and are far more important than the prints themselves!
The better way to go is to have yuor pics downloaded from your memory card to a CD. This can be done at the camera shops which are located near the entrances to all 4 theme parks. Cost is $12.99 per CD, limit 120 pics per CD (so if you take more than 120, you will have to pay for 2 CDs). Then you can clear your memory cards ad keep shooting.
The CDs can then be used to have your pics printed when you get home, either at the local place of your choice, or by using one of the many online printing services like Shutterfly or Ophoto. You will have the added benefit of ordering all of your prints at one time, possibly qualifying you for bulk printing discounts.
If you have a car, you can also have your pics downloaded to CD at any of the Walgreens stores in the WDW area. All of the nearby Walgreens have 24-hour photo counters, and the downloads there are only $3.99 per CD, for as many pics as the CD will hold.
Remember - guard the files with your life!
