She means to keep prices down (3)
I believe the answer is:
peg
'she' is the definition.
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for peg that I've seen before include "Small dowel" , "Kind of pin for hanging clothes" , "Short pin or bolt" , "The girl to hang your hat on" , "Brandy and soda drink measure" .)