The cost includes a court for rehearsal (8)
I believe the answer is:
practice
'rehearsal' is the definition.
(thesaurus)
'the cost includes a court' is the wordplay.
'the cost' becomes 'price' ('price' can be a synonym of 'cost'**).
'includes' indicates putting letters inside.
'court' becomes 'ct'.
'a'+'ct'='act'
'price' enclosing 'act' is 'PRACTICE'.
'for' acts as a link.
(Other definitions for practice that I've seen before include "Habit - procedure" , "Customary procedure" , "It makes perfect, 'tis said" , "'....... what you preach'" , "Routine" .)