Just a little clarification. WinCNC with hardware is $1100 more than Mach3 using the parallel port. You can easily spend $1500 more on WinCNC to do things that Mach3 can do stock, like Probing, Tooolchange, and Tangential knife support.
And there are multiple hardware pulse generators available for Mach3, which basically make it very similar to WinCNC in operation. These range in price from under $100 to about $1000. The most popular are under $250.