Hi Janet
I don´t see any standard way to bring the cost into SNP via CIF.
I would prefer to use APO BW solution. You can create couple of time series KFs in SNP planning book. One i.e. cost/piece you can load into KF which you can hide in planning book and see you if you can right a macro cost/piece * stock (projected stock and safety stock KF) and show in the planning book.
I hope this solution will help you.
Thanks
Amol