The overheads of setting up characters in populist society (5)
I believe the answer is:
costs
'the overheads' is the definition.
(I've seen this before)
'setting up characters in populist society' is the wordplay.
'setting up' says the letters should be written backwards.
'characters in' says the answer is hidden in the clue.
'stsoc' is hidden in the letters of 'populist society'.
'stsoc' backwards is 'COSTS'.
'of' acts as a link.
(Other definitions for costs that I've seen before include "Fees" , "Expenditure" , "Is priced at" , "prices" , "Overheads" .)