Beware of the seller of sealed new in box Nest thermostats. There is a guy doing daylight scoop and runs on these. He recently got an armful of them from a major Calgary heating wholesaler. Walked right in and scooped up the pile from the shelf and ran to an awaiting car (with stolen plates of course). I don't deal with every wholesaler, but I wouldn't be surprised if he has hit multiple stores.
I am not sure if the serial number and the thermostats are trackable and can be rendered useless once hooked up to wifi.