Crossword Genius

Small beer in exchange for money (4)

Ross

I believe the answer is:

sale

Here is my best explanation:

'exchange for money' is the definition.

'small beer' is the wordplay.
'small' becomes 's' (abbreviation - e.g. clothes size).
'beer' becomes 'ale' (I've seen this before**).
's'+'ale'='SALE'

'in' is the link.

This clue was last seen in The Times