on parts.ford.com, they list the CCD front/rear shocks at $412.36, and standard at $125 front /$155 rear. If you just need to replace one, it won't be too much of a difference to get a replacement CCD shock then to replace the pair on the axle, which i expect at minimum you need to change out the axle. Also, they have different CCD part numbers depending on if you have standard length or extended.
Also, I don't know in what setting the other axle will run at if you disconnect the CCD and have a mismatch of CCD / non-CCD.
If the price is still a concern, check ebay or maybe junkyards for any Expeditions. It just seems like a big pain to do part of a conversion to non-CCD without knowing the impacts on the vehicle dynamics.