Money for stamp (4)
I believe the answer is:
coin
I believe this clue is a double definition.
'money' is the first definition.
(I've seen this before)
'stamp' is the second definition.
(I've seen this before)
'for' acts as a link.
(Other definitions for coin that I've seen before include "Metal piece of money" , "Create (phrase); metal token" , "Make up" , "Fabricate" , "Metal currency" .)