Evidently there’s cash in road-building (6)

I believe the answer is:

dollar

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'evidently there's' is the definition.
I can't tell whether this defines the answer.

'cash in road-building' is the wordplay.
'cash' becomes 'll' (I can't justify this - if you can you should believe this answer much more).
'in' indicates putting letters inside.
'building' indicates anagramming the letters.
'road' anagrammed gives 'doar'.
'll' put within 'doar' is 'DOLLAR'.

Can you help me to learn more?

(Other definitions for dollar that I've seen before include "Greenback; buck" , "US currency" , "Monetary unit in several countries" , "100 cents" , "US monetary unit" .)

I've seen this clue in the Evening Standard.

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