Terrible avarice is perhaps a staple for the rich? (7)
I believe the answer is:
caviare
'perhaps a staple for the rich?' is the definition.
(caviare is an expensive delicacy)
'terrible avarice' is the wordplay.
'terrible' indicates anagramming the letters.
'avarice' anagrammed gives 'CAVIARE'.
'is' acts as a link.
(Other definitions for caviare that I've seen before include "Roe as delicacy" , "Salted roe" , "Expensive delicacy" , "eggs that can be expensive" , "Sturgeon roe" .)