I don't know if this helps, but I called customer service when I was thinking about gettting the legs of my Samantha (actually soon-to-be DD's Samantha) re-strung. I specifically asked if the cost ($20) was per limb. The woman I spoke with said no, that the $20 would cover restringing of all the limbs. She also said that they would give her a general cleaning. From what I have read in the past, if you do decide to have all limbs re-strung, you should probably write a note asking them to do so.
I have decided not to re-string our Samantha. I am not sure if I would have been brave enough to do the re-stringing myself, but I was considering it, and I will consider it again if DD eventually wants it done (Samantha's toes point in a bit).
Good Luck!
Shawn