TP-Link Tapo Mini Smart Plug P100 (4 Pack) $38 ($28 with $10 Perks Voucher) + Delivery ($0 C&C/ in-Store) @ JB Hi-Fi

Retailer (per OzBargain): Electrical & Electronics. Should be a good deal if you have $10 perks voucher. Comes down to $7 for each smart plug. - Spotted on OzBargain's front page. Click through to see the discussion + votes.