Cost per act I fixed, good (5,3)
I believe the answer is:
price tag
'cost' is the definition.
(thesaurus)
'per act i fixed good' is the wordplay.
'fixed' indicates anagramming the letters.
'good' becomes 'g' (abbreviation).
'per'+'act'+'i'='peracti'
'peracti' with letters rearranged gives 'priceta'.
'priceta'+'g'='PRICE TAG'
(Other definitions for price tag that I've seen before include "This shows what it should cost" , "shows outlay required" , "Amount to be paid" , "Label showing cost" , "damage shower" .)