Actually, it just need you to transfer the photos from camera to computer, and then add them to iTunes library, then sync them to iPad 3 with iTunes, just so easy.
If you are talking about the Camera Connection kit, yes it is worth it for the sake of convenience and the ability to see your photos immediately on your iPad. Konoo's way is the alternative.
I got a cheap camera connection kit, and it does it's job, and it's worth it, cause I can just transfer photos from camera, straight onto iPhone, I dunno if I can link you to where I brought mine, but mine was not from the Apple shop.
