One right, say, to retire, with church living no longer very profitable (3-4-5)
I believe the answer is:
get-rich-quick
'very profitable' is the definition.
(as in a get rich quick scheme)
'one right say to retire with church living no longer' is the wordplay.
'one right say' becomes 'irteg' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'to retire' shows that the letters should be reversed in order (retire can mean to go back).
'with' means one lot of letters go next to another.
'church' becomes 'ch' (common abbreviation).
'living no longer' becomes 'quick' (archaic term meaning 'living' or 'alive').
'irteg' written backwards gives 'getri'.
'getri'+'ch'+'quick'='GET-RICH-QUICK'
Can you help me to learn more?
(Another definition for get-rich-quick that I've seen is " Leading (dishonestly?) to easy prosperity".)