I do not believe that Radio Shack carries Ferric Chloride any longer in the local stores. I got the last two bottles at the RS in Wasilla; I think they were just leftovers collecting dust on the shelf.
It seems you can order it online:
http://www.radioshack.com/radioshack-16oz-pcb-etchant-solution/2761535.html#.VG_n-GPiupo
It's also used in woodwork; you may be able to source it from specialty woodworking outfits as well.