Traffic unit releases information about dance giving price reduction (5,8)

I believe the answer is:

trade discount

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'reduction' is the definition.
(thesaurus)

'traffic unit releases' is the wordplay.
'traffic' becomes 'trade' (traffic can mean illegal trade).
'unit releases' becomes 'discount' (I can't justify this - if you can you should believe this answer much more).
'trade'+'discount'='TRADE DISCOUNT'

'information about dance giving price' acts as a link.
This may not be right. Some or all of it may belong to another bit of the clue.

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I've seen this clue in The Irish Times.

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