Don't know the current price but not cheap compared to a basic alarm. First bought in 2003 when there were not as many automation options as it is more than just an alarm with its own logic engine.
As per my previous post I use a Cytech Comfort alarm and it is full integrated with Home Assistant. I have an Ethernet interface for the alarm and run a Python script that is a MQTT bridge, see here: https://github.com/koochyrat/comfort2.
For the T series new and old I use a Cabstrut pedestal cover plate with a 75x50 cut out behind the switches-see pic. For single switches I use the Sonoff mini in the wall box with the CBI dimmer switch as it has a nice action but is not a toggle.