I'm new to this caper and I wondered if the reason no one put this up earlier was because of the reliance of the entertainment book (or other) discount. In saying that though, DJ's has had the KSM150 for $639 for a while now, and during Mother's day period had the Spiraliser attachment for free. Currently (11am 16/5/16) the deal is still on online but it says the spiraliser is out of stock. Don't know if that means you can still get the deal and get the spiraliser when they replenish stock.
Anyway the nitty gritty of this "deal" is:
10% off using entertainment book(these vouchers take a day or two so you may be a risk if you are making a play for a spiraliser) $575.1
if you are lucky enough to know someone who works at DJ's they can get a further 10% off by claiming off the receipt (to be confirmed)
*shout out to qantas21 too for also mentioning this deal in the Myer thread https://www.ozbargain.com.au/node/247958
I hope I filled this out properly.
I don't think you get cashback when using gift cards. It is one or the other.