I don't think you an buy the pieces individually if that is what you are asking. You can buy the three piece set though for only $149 as nsstang stated.
The part number for the "chin splitter" (lowest portion of the spoiler assembly) is DR3Z-63001A04-AA. They're available from (the dealer formerly known as) Tousley for $119.
FWIW, I think DR3V-001A04-AC3JA6 is the number for the complete 3-piece front spoiler.