The price of a bed round the south (4)
I believe the answer is:
cost
'the price' is the definition.
('cost' can be a synonym of 'price')
'a bed round the south' is the wordplay.
'a bed' becomes 'cot' (cot is a type of bed).
'round' is an insertion indicator.
'the south' becomes 's' (abbreviation).
'cot' placed around 's' is 'COST'.
'of' is the link.
(Other definitions for cost that I've seen before include "penalty" , "Be priced at" , "Suffering" , "Amount required as payment" , "Fee" .)