I asked you to compare a WIndows server with unlimited client licensing that THAT is what you come up with? I guess you're unaware that even the basic Mac Mini with standard Mac OS X (NOT the server version) will do everything Windows Home Server will do.
The Mac Mini server has a full blown Mac OS X Server with unlimited client licenses. That makes is suitable for small businesses or other file serving applications. The equivalent WIndows server with just 25 client licenses is over $2,200:
You could buy TWO Mac Mini servers with UNLIMITED client licenses for less than the software cost alone for Windows.
Or, if you want just the software, Mac OS X Server with unlimited client licenses is $499 - 1/4 the cost of the 25 user WIndows software.
So much for the 'Apple tax'.