Security System Touchscreen new account

I have lived with my mom and had an xfinity account under my name including a security system which has 5 sensors, a camera and a touchscreen. We purchased this outright with Xfinity when we set it up for about $500. I'm now moving out and creating a new account for my mom under her name. Nothing of the security system will be changing except it will be moved to her name. We went to Xfinity and we were told that we now have to get a $300 touchscreen since this is a new account. Is this true? Isn't it possible to just reset it since it's under my name and I'm leaving it to her at the same location?

I don't understand why we could purchase it outright and now since it's changing the account at the same place, we would have to buy a new one. It defeats the purpose of even purchasing for the home. Need confirmation that we can just factory reset it and just assign it to her. We are having a tech come and put it under her account and she was not advised it would cost $99.

what are my options?