Buy tea, going into wallet (8)
I believe the answer is:
purchase
'buy' is the definition.
('purchase' can be a synonym of 'buy')
'tea going into wallet' is the wordplay.
'tea' becomes 'cha' (cha is a type of tea).
'going into' is an insertion indicator.
'wallet' becomes 'purse' (I've seen this before).
'cha' inserted inside 'purse' is 'PURCHASE'.
(Other definitions for purchase that I've seen before include "secure an advantage" , "Shop successfully" , "Acquire" , "that has gone through the barcode reader?" , "Leverage" .)