Bought back, having had second thoughts? (8)
I believe the answer is:
redeemed
'bought back' is the definition.
('redeem' can be a synonym of 'buy back')
'second thoughts?' is the wordplay.
'second' becomes 're' (prefix meaning second in eg review, re-education).
'thoughts?' becomes 'deemed' (I am not sure about this - if you are sure you should believe this answer much more).
're'+'deemed'='REDEEMED'
'having had' acts as a link.
This may not be right. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for redeemed that I've seen before include "Saved from sins or bought back from the pawnshop" , "Made up for; bought back" , "Restored to favour" , "Saved as from hell or pawnshop" , "free from error" .)