Saw this as a Facebook ad. It doesn't look like there's a minimum spend to qualify for free shipping.
The discount is applied automatically at checkout.
Ends Midnight 31st August.
Beans work out to be $38.25/kg or $34/kg if you get the 2kg Challenge Pack.
They also have the original Aeropress as an add-on (you'll have to buy coffee) which works out to be $37.40 after the discount.
I haven't tried them yet but have tried Adore.
Killer coffee has a great taste, 10/10 would recommend if you like strong coffee that is not bitter tasting.