Container raised price for salt (7)
I believe the answer is:
nitrate
'salt' is the definition.
(nitrate is a kind of salt)
'container raised price' is the wordplay.
'container' becomes 'tin' (tin is a kind of container).
'raised' is a reversal indicator (going up in a down clue).
'price' becomes 'rate' (I've seen this in other clues).
'tin' back-to-front is 'nit'.
'nit'+'rate'='NITRATE'
'for' is the link.
(Other definitions for nitrate that I've seen before include "following 28 [SILVER]" , "salt" , "Compound" , "Fertiliser chemical" , "Natural or synthetic fertiliser" .)