Concerned with rent? Save! (7)
I believe the answer is:
release
'save' is the definition.
(thesaurus)
'concerned with rent?' is the wordplay.
'concerned with' becomes 're'.
'rent?' becomes 'lease' (I've seen this before**).
're'+'lease'='RELEASE'
(Other definitions for release that I've seen before include "press announcement" , "loose" , "record" , "Prisoner eagerly awaits this" , "New film" .)