To articulate further the point made by nbevan, Macs generally require the user to have deeper pockets that PCs do - particularly when it comes to peripherals. Stuff like losing a power adaptor or cracking your screen can be eye-wateringly expensive compared to doing the same on a PC. And unlike PCs, you can't always wander down to PC World or Maplin and find a huge range of cheap components made by different suppliers; often you're stuck with the pricy Mac Shops and genuine Apple products.

Is it worth the extra? Yeah, of course - but you should bear it in mind that if economy computing is what you're about, go with a PC.