Only ~3 million Amigas was ever sold, such numbers is pittance compared IBM's PS/2 sales.
Indeed, and how many of those above machines would have been sold without the millions upon millions of $ put into its advertising every year?, i'd go as far to say that the PS2 has had more money put into it's advertising in 1 year than the Amiga as ever had since it was concieved, easily.
But yeah we can't compare there sales, but we can sorta have a nice stab at the actual figures of Amigas sold, and its alot more than 3 million, if you double it you will prolly be alot closer.