Cheek smuggling in ecstasy at low price (5)
I believe the answer is:
cheap
'at low price' is the definition.
(cheap means sold at a low price)
'cheek smuggling in ecstasy' is the wordplay.
'cheek' becomes 'chap' (chap can mean part of an animal's cheek).
'smuggling in' is an insertion indicator.
'ecstasy' becomes 'E' (informal term for the drug).
'chap' placed around 'e' is 'CHEAP'.
(Other definitions for cheap that I've seen before include "Base" , "not doing much damage" , "A snip" , "Shoddy" , "Second-rate" .)