A Mac Mini is much cheaper, even after you get a monitor/keyboard/mouse.
And it looks pretty cool. And takes up a lot less space than my Windows and Linux boxes. (Of course, I can't open it up and tinker with it.)
And it is a very stable machine.
Since I brought my Mac Mini online (February), I've only had to reboot it three times. Two times were because of core OS updates and the third was because, being the brilliant screw up only a 'smart' programmer can be, I used the command line to kill a process that was hung, but killed the wrong one and really hung the entire computer.
My Linux box has running continuously for too many months to remember.
My Windows box (in my 'office') has spontaneously rebooted (blue screen of death) or had display/keyboard scrambles about 2 to 3 times a week. My 'home' Windows box only reboots about once every couple of weeks.
Yup, Mac (which is actually *nix based) and Linux are way more stable.
The back of my iPad (two months old) says 'I have joined the dark side...' and I am finding that it works nicely.
Cheers,
Ancient Lady