Crossword Genius

Below the normal price is clearly a destruction (8,4)

Ross

I believe the answer is:

discount rate

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'clearly a destruction' is the definition.
I can't judge whether this defines the answer.

'below the normal price' is the wordplay.
'below' means one lot of letters go next to another (in a down clue, some letters go below others).
'the normal' becomes 'discount' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'price' becomes 'rate' (I've seen this before).
'discount' put next to 'rate' is 'DISCOUNT RATE'.

'is' acts as a link.

Can you help me to learn more?

I've seen this clue in the Sydney Morning Herald.
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