Ringing to get the cost (4)
I believe the answer is:
toll
I believe this is a double definition.
'ringing' is the first definition.
(thesaurus)
'the cost' is the second definition.
(toll is a kind of cost)
'to get' is the link.
(Other definitions for toll that I've seen before include "cost" , "Charge for using, eg, road" , "Spout" , "Charge for passage" , "Be inclined" .)