We've helped several clients sell their professionally installed smart home systems with their homes. For right clients, it can be a boon, some dont want it. However, You're likely to get dinged or lose money with a DIY system in a home. We sell high-end pro systems ($100k+ systems, pro lighting from Lutron/Crestron, etc) sometimes those dont get what we wish, but they last decades and do add value. A DIY system is almost already obsolete, not centralized and difficult to maintain and control(was DIY installed, no warranty, no one to call, pros dont mess with DIY). Your giving it away as it really adds cost, as they have to remove, maintain and/or deal with it. And remember, anything fastened to or a "fixture" to the house MUST be sold with the house, if it is shown to prospective buyers that way. This is a legal thing. So a tv mounted to a wall, light switches, appliances, in ceiling speakers, etc are part of the house and part of the sale. If you want to take those with you, you have to remove them before showing. You cannot tell people its not part of the house, once it is shown with it, either. They can sue you and win, worst case. Seen this happen.