Scots upset by prices (5)
I believe the answer is:
costs
'prices' is the definition.
('cost' can be a synonym of 'price')
'scots upset' is the wordplay.
'upset' is an anagram indicator.
'scots' is an anagram of 'COSTS'.
'by' acts as a link.
(Other definitions for costs that I've seen before include "Charges" , "Expenditure" , "Legal expenses" , "Expenditures, outlays" , "Fees" .)