Yes, if you pre-purchase its cheaper, that's the only difference. I didn't know about the CD before our trip last year, we had several photo pass photos taken at various parks, but not enough to justify the cost of the CD, so I just bought two 5 x 7 prints after the fact. What I learned later that is key info is that you can have a zillion photos on the CD and its still the same price! So, now that I know that it makes the CD much more appealing and I am willing to spend $100 on pre-ordering the CD and we will make sure to hit up every photopass photographer we see! Some even took more than one shot of us, like a close up or different pose, or something, so I won't be shy to ask for those. I think photopass is great. My DF and I travelled just the two of us, and that will be the case for our honeymoon next year, and its nice to have pics of the two of us together without always annoying an innocent passerby to take a photo of us (though most people don't mind!) And the photopass people are at key spots, so you can get that nice shot with the castle in the background, etc.
Also, the card they use looks like your resort room key, a plastic thing they just scan quickly and it registers your number. We had more than one card and you can combine them to create one CD.
This is a really informative site on everything photopass.
http://www.stitchkingdom.com/disneysphotopass/
And this is straight from the official photopass website: (
www.disneyphotopass.com)
Q. I heard the PhotoCD is a good deal. Is there a limit to the number of photos you can have on a PhotoCD?
A. No. Get as many photos taken as you want and you can have them all on a CD! The price is the same regardless of the number of photos in your account. Note that Disney's Gallery photos and any uploaded photos will not be included on your PhotoCD.
Q. Are the ride photos included on Disney's PhotoPass system?
A. With the exception of Test Track at Epcot®, no. On Test Track you can add your photo to your Disney's PhotoPass card as you exit the attraction.
Hope this helps!!!