Kogan First exclusive pricing, cheapest is 4 pack kit @ $15.50 per downlight. I think it's pretty cheap for Smart Lighting.
Kogan First also on special this week, $5.99 instead of $11.99 per month until 18 April, so instead of paying for postage, paying for Kogan First pretty much paid itself in 1 delivery.
Does the app support choosing a colour temperature by number, or are you limited to using a slider?