I may have gotten confused by your original posted in thinking you were looking to include the Home Monitoring Service, since you compared it to professional monitoring pricing.
If you’re looking to just self-monitor cameras and not the home monitoring service on top of that, then it’s just $15 a year per camera. If you are looking to include home monitoring service into your setup then that will include a single cam plus license with it for $50 a year. Again however, camera triggers cannot set off the alarm nor alert the monitoring company. It will only alert your phone in which you can then set the alarm off from manually if for whatever reason one of the entry detection devices linked to the home monitoring hub was bypassed.
But you also mentioned less than 12-second monitoring. The cameras will provide you with motion-trigger recordings up to 12 seconds long with a cooldown period of five minutes for free. You don’t need any service if that’s all you’re looking to get from the cameras.