PetCulture currently having a 30% off on Spectrum Sentinals plus other bits and bobs.
Further 10% off if you choose 'Auto Delivery' which brings it down to $114.65.
Also sign up to PetCulture and link up Everyday rewards card. You'll get emailed a unique code for a further 15% off plus a bonus 5000 points off your first order.
All in all, got it Metro delivered for $97.45.
Prices before 'Auto Delivery'
Spectrum blue (L) - 12 pack $137.19
Spectrum green (S) - 12 pack $117.24
Spectrum brown (XS) - 12 pack $109.54