Trackmaster Alfie Research

Yes $650-$850 is correct, but having the only one for sale on eBay makes yours the newest litmus test. 
Stay firm unless you really need to sell them quick, or find someone deserving of a good deal that will really cherish it. 
It’s a weird time in collecting. 
A large majority of the kids who played with these toys back in 2006 are now 18-30 years old. 
The younger ones are selling off their childhood toys, while the older ones are broke but about 10 years away from having the established lifestyles and money to really start buying them all back. 
It seems like we are currently in the in between stage though, with less rarities coming up, but also less buyers. 
There are still a few hard core collectors out there but the TrackMaster genre has also been been dead for over 10 years now, granted it should have never have been killed and that’s why people still love it and collect it, but what Alfies absolute ceiling is and when or if the well is running full or dry is speculation for your own contemplation.