This is the much-loved headphones on OzBargain now at David Jones for a reasonable price.
Black version same price: https://www.davidjones.com/Product/22200990/WIRELESS-NOISE-C...
Silver version: https://www.davidjones.com//22200991/WIRELESS-NOISE-CANCELLI...
You can get 10% off DJ gift cards and use them to buy these with AGL rewards or Lumo Ameego rewards.
Please see https://www.ozbargain.com.au/wiki/discounted_egift_cards more ways to get discount DJ gift cards through reward programs.
I don't believe Cash rewards is giving out cashback for DJ electronics.