I have a similar dilemma... but i haven't been able to hear a price today. Does sound a bit pricey for "simple". The coolest thing i've seen about SILC is that the home owner has some control of the system setup. https://www.youtube.com/watch?v=vbrYVn_ZPqE

I also heard that C-bus could be around $15k, which is much more sophisticated. Push (also clipsal) seems interesting too, but the wireless seemed slow in the micro-sized showroom i drove across town to see (Clipsal Powerhouse is a misleading term i think). I'm finding so little information or access to demonstration systems, that i'm really getting over chasing Clipsal. Other systems i'm looking at are Philips Dynamite, Zigbee, Z-wave, Dali... but most of these need system integrators (like C-Bus), which probably bumps up the price and flexibility.