Costs of rings (5)
I believe the answer is:
tolls
I believe this clue is a double definition.
'costs' is the first definition.
(toll is a kind of cost)
'rings' is the second definition.
(tolling is a kind of ringing)
'of' is the link.
(Other definitions for tolls that I've seen before include "Chimes mournfully" , "Road charges" , "Hemingway novel 'For Whom the Bell . . . . .'" , "bars" .)