Fight here to value jewellery (5,4)
I believe the answer is:
prize ring
'fight here' is the definition.
(I know that contend is often done in prize ring)
'value jewellery' is the wordplay.
'value' becomes 'prize' (synonyms).
'jewellery' becomes 'ring' (ring is a kind of jewellery).
'prize'+'ring'='PRIZE-RING'
'to' is the link.
(Other definitions for prize ring that I've seen before include "Fight Club venue?" , "boxing" , "opponents boxed in here" .)