alarm.com doesn't deal directly with the public, you have to go through a reseller which is typically an alarm installation company, or a DIY alarm supplier. I'm paying $28/month but my accounts are grandfathered in at the price I started at. I think the same level of account is around $35/month now. I use Advanced Security LLC and am very happy with them; they've helped me at night and weekends and are very responsive. But you can search for alarm.com resellers, there's plenty of them out there.
Yes, but you don't need a cellular account. The alarm.com monthly fee includes the cost of the cellular data connection. There's AT&T and Verizon versions so you can choose what carrier has the best (or only) signal at your particular location.
I'm waiting to see whether or not HE will add the ability to open a raw encrypted socket. Right now, my HE driver depends on a Node Red flow which uses openssl to talk to the alarm panel, then uses a MQTT broker to push the data to HE. It works, but it's clunky and unnecessarily complicated and of course, requires a platform to run Node Red on (I'm running it in a Docker container on my Synology NAS).
There's no way at present for HE to talk directly to the alarm panel. If HE doesn't add encrypted socket support, at some point I guess I'll clean up the Node Red flow and publish it along with the driver. But a HE-only solution would be much better.
