Clue: Extremely devious setter's rising in value — Logodaedalus, say (9)
Answer: WORDSMITH
Explanation: Definition: Logodaedalus, say
 [ **1st and last letters of**(Extremely) "devious" + **reversal of**(…'s rising) I'M(setter is/I am, with the setter using the self-referential pronoun)] **contained in**(in) WORTH(value/merit).
Defn: An example of which/say, is Logodaedalus, a crossword setter.