Expensive - soak (5)
I believe the answer is:
steep
This clue is a double definition.
'expensive' is the first definition.
(I know that expensive can be written as steep)
'soak' is the second definition.
(I know that steep is a kind of soak)
(Other definitions for steep that I've seen before include "Marinate" , "Precipitous - outrageous" , "Hard for cycling" , "Difficult" , "Rising sharply" .)