Buy! Did you open a can of worms!
My career background includes support for both Mac and PC hardware. From a a support standpoint, Macs are a lot easier to support. If you compare speeds, the PC marketplace used to have the edge. Nowadays, with the MacOS nearly 100% Unix, that isn't the case.
Price wise, Macs still cost more than PCs. And, a lot more software is available for PCs, than there is for Macs. However, that is starting to change, especially in the last several months; favoring Macs.
Processing speed belongs to Macs. The major reason has to do with with Unix, which will always be faster than any PC-DOS OS. Pundits to the contrary, even Windows 8 is still DOS based.
MS is slowly but surely transforming themselves to a service support related company. That should be a major consideration if you can't fix issues yourself.
Obviously, any one contemplating a new computer should weigh all of the alternatives. You should do the same.