Wearing them, one close to royalty must be rich (2,3,5)
I believe the answer is:
in the money
'rich' is the definition.
(thesaurus)
'wearing them one close to royalty' is the wordplay.
'wearing' becomes 'in' (wear in (and 'in' is fashionable)**).
'close to' says to take the final letters (the close/ending of).
The final letter of 'royalty' is 'y'.
'in'+'them'+'one'+'y'='IN THE MONEY'
'must be' acts as a link.
(Other definitions for in the money that I've seen before include "Suddenly rich" , "rolling" , "Very wealthy" , "Flush" , "Well-off" .)