Okay, I understand I need to go from my Solidworks software, to a cam software, to Mach3.

But, which Cam software is the best to work with Solidworks, yet, cheap? Cheap, as in under $500

I will be using 3 axis with a 4th axis added later in the future.

I was thinking Artcam Express, but it doesn't seem to do 4th axis?

Any help is appreciated, thank you.