Act in your own best interests: perform singles with comics at fair (4,4,5,5)

'act in your own best interests perform singles with comics at fair' is the definition.
I know nothing about this answer so I cannot tell whether this works.

'perform singles with comics at fair' is the wordplay.
'perform' becomes 'play' (playing is a kind of performing).
'singles' becomes 'ones' ('one' can be a synonym of 'single').
'with' says to put letters next to each other.
'comics' becomes 'cards' (card can mean a comic or eccentric person).
'at fair' becomes 'right' (I can't justify this - if you can you should believe this answer much more).
'play'+'ones'+'cards'+'right'='PLAY ONES CARDS RIGHT'