I use Insteon at home as well. Budget $75 per control point, and $500 for the controller. I use the ISY controller, and it is a piece of junk, but it does the job. There isn't the variety of sensors, switches, devices, and accessories I wish there was, some older devices are a pain with low-power loads, and the plug-in devices are generally a pain in the ass. Programming is clunky, but not that hard.
I still haven't put it into our vacation home, holding out for something better. Two years later, still no progress...
My biggest complaint is that it is hard to "extend" Insteon. I wish I could integrate with Sonos, and I wish I had a simpler way to do a password-free web interface. (Hard, not impossible if you really want to work for it...)