Today I finally ordered the Taptotalk I can hardly wait to get the starter pack. I have already started setting up the images and sounds so that when the starter pack gets here I will have some things in place for Emily. I figure we can see how it goes and let her direct what words to add/subtract.
The Taptotalk guys were very helpful over the phone.
OH and if you are looking for a cheaper DS try your local Gamestop for a used one.