Regularly dirt-cheap around Greek island (6)
I believe the answer is:
ithaca
'greek island' is the definition.
(I've seen this before)
'regularly dirt-cheap around' is the wordplay.
'regularly' means one should take alternating letters (regularly take one letter, leave next etc.).
'around' becomes 'ca' (circa).
'dirt'+'cheap'='dirtcheap'
The alternate letters of 'dirtcheap' are 'itha'.
'itha'+'ca'='ITHACA'
(Other definitions for ithaca that I've seen before include "Greek island sought by Ulysses" , "Birthplace of Odysseus" , "In Homeric legend, Odysseus was its king" , "Odysseus's home" , "Where Ulysses was produced" .)