Connoisseur's top bid for chest (6)
I believe the answer is:
coffer
'chest' is the definition.
(coffer is a kind of chest)
'connoisseur's top bid' is the wordplay.
'top' indicates taking the first letters.
'bid' becomes 'offer' ('offer' can be a synonym of 'bid').
The initial letter of 'connoisseurs' is 'c'.
'c'+'offer'='COFFER'
'for' is the link.
(Other definitions for coffer that I've seen before include "Treasure chest" , "Chest for storing valuables" , "safe" , "Strongbox" , "Money chest sounds like one with lung trouble" .)