Where would one buy a NEW but older version of a MacBook Pro?

I am searching for a late 2011 Macbook Pro 17" 2.5GHz. Bestbuy said I need to order them from Apple but alas the Newest version of the MacBook Pro is out and not in the Apple store anymore. Does anyone know where you buy older versions of Apple MacBook Pros that are customed and still in the box NEW?

much appreciated,

-Darrin