spoiled.When you hear rare breed,that's not saying that they are rare and hard to find.
There are 7 groups that dogs are classified under.So alot of the times these dogs(rare) are not classified under them.So they have them under the rare breed.
Dogs in these groups were raised and trained for certain jobs...
There are also dogs no recognized in the kennel clubs.
So when you have a mixed breed.Say a Rottie and lab.You are getting a working dog and a sporting dog all in one.
Here is a link that may help you.
Rare breeds just more or less mean that they are not recognized under the 7 groups.