Pay for exhibition area at fair (5)
I believe the answer is:
stand
I believe this clue is a double definition.
'pay for' is the first definition.
(as in to stand someone a drink)
'exhibition area at fair' is the second definition.
(as in a stand or display at a fair)
(Other definitions for stand that I've seen before include "group of trees" , "Remain upright" , "Watch and do nothing to help" , "stay the same in position" , "partnership" .)