Frederick C. Wilt said:
The M1 is primarily a security system with a little bit of automation added in.
If you are not going to use it AS a security system then I would never suggest it as the basis of a home automation system.
For example in my home I have an M1 as the security part of my system but the primary automation system is based on Elan g! hardware.
You have expressed concern about costs - good home automation, in general, is expensive. To date I've invested well in excess of $35K.
So what is it that you want to do? Knowing that will lead us to the correct hardware.
I wouldn't say nix the Elk if you're doing all of the HA elsewhere. The Elk integrates very nicely with 3rd party automation products, and it's very flexible. I still use some of the automation rules on the Elk to supplement the Vera. For example, I use a phantom output that changes state based on whether or not the chime is off which allows the Vera to make decisions on whether or not to speak voice alerts. I use tasks to automate some arming and disarming and control relays. I looked at other options when I moved, but I liked my Elk so much, I ended up buying an installing another one 2 weeks ago, knowing full well that nearly all of the automation was going to happen with the vera. It's a good system. As far as flexibility goes, HAI is really the only other choice from what I've seen. I definitely don't think he made a mistake buying the Elk.
As far as wired/wireless I/O for the vera, it will communicate to other devices over the network (like my Ecobee thermostats), you can add USB->serial adapters and connect it to equipment that way (this is how it communicates with my lighting controller), and it's got a built in Z-wave radio (my locks and a couple of switches). All of the automated lighting technologies out there have their strengths and drawbacks. Some people are going to tell you Z-wave sucks. But, I've had no issues with it (other than some GE switches having crappy build quality). And there is a TON of devices that are Z-wave capable, far more than any other technology. AND, you're not locked into a specific vendor for equipment. (Dont' like GE switches, buy another brand).
The nice thing about the Elk plugin for the Vera is that the vera gets realtime updates for sensors. So instead of having to buy a bunch of Z-wave sensors, it uses the alarm sensors instead (or in addition to). Sense motion in the garage after dark? Turn on the garage lights until you don't see motion for 5 minutes. Nursery door opens in the middle of night, fire off a voice alert that tells the kids to go back to bed because it's not time to get up yet.
Another thing the Elk has going for it is that it's easy to configure with ElkRP. I'm not sure what other vendors have, but I know some of them require programming through the keypad. I had an old Ademco system many years ago that was like this, and it sucked to work with.