Money matters to 9 across, as it's a taxing job (7,8)

I believe the answer is:

finance minister

I'm a little stuck... Click here to teach me more about this clue!

'money matters to 9 across as' is the definition.
I can't judge whether this definition defines the answer.

'a taxing job' is the wordplay.
'a taxing' becomes 'finance' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'job' becomes 'minister' (minister is a kind of job).
'finance'+'minister'='FINANCE MINISTER'

'it's' acts as a link.

Can you help me to learn more?

I've seen this clue in the Irish Times and the Irish Times (Crosaire).

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