One has to be uncommonly rich to do so (4,4,1,4)
I believe the answer is:
live like a lord
'one has' is the definition.
I don't know anything about this answer so I can't tell whether this works.
'be uncommonly rich to do so' is the wordplay.
I cannot really see how this works, but
'be' could be 'live' (living is a kind of being) and 'live' is located in the answer.
This may be the basis of clue (or it may be nonsense).
'to' acts as a link.
Can you help me to learn more?
(Another definition for live like a lord that I've seen is " Have lavish lifestyle".)