Routine move to divide cost (8)
I believe the answer is:
practice
'routine' is the definition.
(I've seen this before)
'move to divide cost' is the wordplay.
'move' becomes 'act' (synonyms).
'to divide' is an insertion indicator (inserted letters divide the word).
'cost' becomes 'price' (the cost or price of something).
'act' going within 'price' is 'PRACTICE'.
(Other definitions for practice that I've seen before include "Rehearsal" , "Doctor's business" , "Habit - procedure" , "Doctor's premises" , "Customary procedure" .)