Mach 3 is $200 and all it does when you purchase is allow you to run more than 50 lines of gcode at a time. And actually there's a limit of 10,000 lines unless you buy the commercial version. It really sucks the only way around this is to divide your code files into 50 line chunks and then have a macro that loads and continues an operation your trying to run. Pretty ghetto if you ask me