Mike,
I know you said it was not in your budget right now, but have you ever considered a Homeworks Wireless system? You could start off slow with one processor and then upgrade going forward. Three processors linked together will get you 192 devices although, you may not need that many as Lutron has real Accessory Dimmers and Switches. Each P5 processor will handle 64 devices and 32 keypads.
And if you have access to fish control wires, a hybrid install of a Series 4 and then use wireless to fill in where you can't fish.
I don't know how big it is, but I know how big my house is and I had 80+ Insteon devices. You either have a large home, or 4 gang wallplates on every wall. :blink:
After all, this is your home and its one thing to like to tweak a few things, but constantly correcting failures is a PITA and really low WAF.
And I can't say enough about the power of the Lutron system. Keypads provide real indications if a zone or scene is on. So even if someone turns off a device, if others in the zone are still on, the keypad indicates such. Plus, like Insteon, a dimmer/switch can also act like a controller. And the dimmers/switches are terminal based, not pigtailed.
And the best part, it is no longer against Lutron's software license for a dealer to provide you with the programming software, so you would be free to program the system yourself.
Yes, it is expensive. Some would consider it very expensive. Dimmers are 5x Insteon, Keypads 3x (and include engraving) plus $1400 for a processor. (A hybrid Series 4/Wireless install would be much cheaper, but you need to be able to run the control wire.) But again, this is your home and getting the best is not cheap.
Just some info for you to think about.