It has grocer's unusual story of path to fortune (4,2,6)
I believe the answer is:
rags to riches
'story of path to fortune' is the definition.
(as in a rags to riches story)
'it has grocer's unusual' is the wordplay.
'unusual' is an anagram indicator.
'it'+'has'+'grocers'='ithasgrocers'
'ithasgrocers' with letters rearranged gives 'RAGS-TO-RICHES'.
(Other definitions for rags to riches that I've seen before include "From poverty to affluence" , ""From poverty to extreme wealth"" , "Story that tells of someone's progression from poverty to wealth" , "(Of story, etc) progress from poverty to wealth" , "signifying good fortune" .)