With fashion, price is not extreme (8)
I believe the answer is:
moderate
'not extreme' is the definition.
(I've seen this in another clue)
'with fashion price' is the wordplay.
'with' means one lot of letters go next to another.
'fashion' becomes 'mode' (synonyms).
'price' becomes 'rate' (I've seen this in other clues).
'mode' put next to 'rate' is 'MODERATE'.
'is' acts as a link.
(Other definitions for moderate that I've seen before include "Slacken" , "Unextreme" , "Read tome (anag) - unexceptional" , "not going to extremes" , "Not excessive or extreme" .)