Speed merchant out to give you a rush? (4,6)

I believe the answer is:

drug dealer

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'out to give you a rush?' is the definition.
I don't know anything about this answer so I can't tell whether this works.

'speed merchant' is the wordplay.
'speed' becomes 'drug' (type of illegal drug).
'merchant' becomes 'dealer' (dealer is a kind of merchant).
'drug'+'dealer'='DRUG DEALER'

Can you help me to learn more?

I've seen this clue in The Irish Times.

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