I grab an appalling deal (7)
I believe the answer is:
bargain
'deal' is the definition.
(synonyms)
'i grab an appalling' is the wordplay.
'appalling' indicates an anagram (an appalling spelling).
'i'+'grab'+'an'='igraban'
'igraban' is an anagram of 'BARGAIN'.
(Other definitions for bargain that I've seen before include "Great deal!" , "Agreement; cheap item" , "Advantageous purchase" , "Thing bought cheaply" , "Negotiate terms" .)