A friend of mine bought a house with an expensive system, but it wasn't very useful and later had a fault. To remove it would require replacing all the switch plates - I would guess $1000 to get rid of it. He was technical so he fixed it instead.
I'm not getting rid of the existing switches and plate covers, so at least I can more easily remediate it if the future buyers don't want the system.
This btw is the source of the word "turnkey". You turn the key, and it works.