Spring fuss? That's rich! (4-2-2)
I believe the answer is:
well-to-do
'rich' is the definition.
('well-to-do' can be similar in meaning to 'rich')
'spring fuss?' is the subsidiary indication.
'spring' becomes 'well' (I've seen this before).
'fuss?' becomes 'todo' (I've seen this in other clues).
'well'+'todo'='welltodo'
'that's' is the link.
(Other definitions for well-to-do that I've seen before include "Financially comfortable" , "Comfortably off" , "Affluent" , "Fairly wealthy" , "Fairly rich, prosperous" .)