I'm going to chime in with the flip side of the coin -- we've never paid for Photopass and I wouldn't generally recommend doing so. On our last trip, we got a Photopass card (not pre-purchased; just the kind they give you, and you can go online later and decide if you want to purchase anything) and had a few dozen Photopass pictures taken. We also carried my camera with me (an ordinary Kodak Easyshare point-and-click) and every time we had pictures taken, we asked the cast member to take some with my camera as well. (That's something I don't think people realize: any cast member you ask, including a Photopass photographer, will be happy to use your camera to take pictures of your family at any time, anywhere. All you have to do is ask.)
I agree. We did this on one of our trips and I just don't see it worth the money to get the cd and then have to pay for your prints on top of it. Yeah, some of the editing options are nice but not worth the overall price.
When we got home we looked it all over, and the pictures we took (or that were taken with CMs by our camera) were better, in almost every case, than the "professional" ones taken by the Photopass photogs, and of course, they didn't cost us a cent. We had also taken a few pictures of the on-screen displays of our better "on-ride photos" (I've since been told that this can be considered a no-no, but I had no idea at the time and no CMs said anything.) and lots of pictures of the scenery, our resort, our dining experiences, etc. We decided that none of the Photopass images were worth buying. Instead, I uploaded about a hundred of our own best photos to Shutterfly and designed a 12"x12" hardcover photobook memorializing our vacation, waited for a Shutterfly seasonal sale, and ordered copies for ourselves and family members for something like $30 apiece, a mere fraction of the $200+ we'd have paid Disney for Photopass and a photo book.
To me, spending money on photography that I can take myself for free (or ask a CM to take), or in the case of stock images, download online for free, would be a waste. However, it's a very individualized decision -- if the special Disney photoshopped images (e.g., your child holding Tinkerbell), on-ride photos, and not having to carry your own camera mean a lot to someone, then certainly I can see how Photopass might be worth it to them. Personally, it's not an expense I can justify.