Unfair treatment when buying salad ingredients? (7)

I believe the answer is:

rawdeal

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

'buying salad ingredients?' is the definition.
I can't judge whether this defines the answer.

'unfair treatment' is the wordplay.
'unfair' becomes 'raw' (similar in meaning).
'treatment' becomes 'deal' (I can't explain this - if you can you should believe this answer much more).
'raw'+'deal'='RAWDEAL'

'when' is the link.

Can you help me to learn more?

I've seen this clue in The Daily Express.

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