I have also automated my new HDB house with Z-Wave system for lighting, air-con and IP camera surveillance. The total cost is less about $2,500, with installation and configuration all done up neatly by this Z-Wave company named eVida.
We did some background research and realize that Z-Wave meets all our requirements. Control4 is prestigious but easily 3 times the price, and LightwaveRF has very attractive price and design, but it is just not functional and easily confuse us of the light state (might cost us more on electricity bill when the lights are left on accidentally).
Thanks to eVida's recommendation, my husband and I eventually chosen the Fibaro HomeCenterLite given its much better and stable phone app to control our smart home remotely. Because when I approached other Z-Wave companies (they shall not be named), I was straight away quoted with the Veralite as a gateway and wasn't given a chance to compare with other gateways. Honestly it is just $200 more for a much much user friendly phone app control and we don't mind to invest this marginal sum.
I like the engineer in eVida. He is really a nice chap with excellent after sales service. And I really mean VERY GOOD after sales service, which is especially important for the not so technically savvy people like me and my husband (ok we understand the basics but can never never set up a system, be it our wireless system or smart home system).
We are very happy and enjoying our smart lifestyle, making our friends jealous when they visit us at our house warming!