Here's a similar Dell
Match specs, warranty, service plans and you'll be close to the same money on any of the all in one's.
You can save if you build your own desktop, but a display the same quality as an apple display is going to cost you.
I've been working on Windows 8 machines and a MacBook Pro R that are about the same money (desktop vs laptop) and the Mac is more reliable and the windows machine is a bit faster. Not enough to make a fuss about, but faster. I think the Windows 8 (an HP desktop) was about$150 less than the laptop if you include the monitor.