Controls costs, following method (9)
I believe the answer is:
moderates
'controls' is the definition.
('moderate' can be a synonym of 'control')
'costs following method' is the wordplay.
'costs' becomes 'rates' (rate is a kind of cost).
'following' says to put letters next to each other.
'method' becomes 'mode' (I've seen this before).
'rates' after 'mode' is 'MODERATES'.
(Other definitions for moderates that I've seen before include "chairs" , "People who don't have extreme views, say about politics" .)