Update:

I started looking into how much I'd have to spend on this project, and I seem to have hit a snag. All of the Insteon modules I've seen require a neutral wire at the switch boxes, and none of the switches I've looked at have a neutral wire available. In some cases there's a nearby outlet that I could pull neutral from, but that probably means ripping my wall apart (no conduit or anything to help me out.)

Anyone have a ballpark estimate of what an electrician might charge to pull neutral wires to my switch boxes? Would they also have to tear the wall up, or is there some trick to it that I'm not aware of?