Customer the pub gets the highest return from? (5)

I believe the answer is:

toper

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'customer the pub' is the definition.
I can't judge whether this defines the answer.

'the highest return from?' is the wordplay.
'the highest' becomes 'top' (I've seen this before).
'return from?' becomes 'er' (I can't justify this - if you can you should give a lot more credence to this answer).
'top'+'er'='TOPER'

'gets' acts as a link.

Can you help me to learn more?

(Other definitions for toper that I've seen before include "Lush" , "Drunkard" , "Heavy drinker" , "Drinker, imbiber" , "Soak" .)

I've seen this clue in the Evening Standard.

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