Purchaser’s place to keep stock of audition (5)
I believe the answer is:
buyer
'purchaser's' is the definition.
('buyer' can be a synonym of 'purchaser')
'place to keep stock of audition' is the wordplay.
'place to keep stock' becomes 'byre' (type of cowshed).
'of audition' indicates a 'sounds like' (homophone) clue (audition can mean hearing).
'byre' is a homophone of 'BUYER'.
(Other definitions for buyer that I've seen before include "Shopper" , "Selector of stock" , "A purchaser, maybe for firm" , "customer" , "store employee" .)