I normally will always recommend Mac because they are user friendly, plug and play and are very rarely susceptible to viruses.
However, because of the vast difference in pay I would have to ask what you plan to use the computer for as far as graphics and software. If you are planning to work with Adobe Suite or other editing software or need any sort of animation capabilities I would say stick with Mac.
There are great refurbished macs available through apple that are still certified by apple along with the apple care options just like with the new machines. Also, if you choose to buy refurbished, it will come preloaded with the most recent OS. If the OS is updated withing 30-60 days (I believe it's still that time frame) they will give you a code that you can download the most current OS.
If you only do rich-text projects such as internet, email, word processing; a Windows based computer is fine, and most likely much cheaper.