Scott-
I think you are on the right track. Keep in mind that with the Mach program and machines that use it like the Tormach there are 1000's of users that are pretty serious but either hobbiest or small company users (like me), and I think you would need a lower cost version to sell to these users, $99. seems right to me, I'd go for it at that price. Keep in mind that from what I understand there are several upcoming new machines that are going to hit the market that also use the Mach control software.
I would consider taking out all the features that aren't really required by the typical Mach user, and all the things you mentioned (DNC, scripting, DFX importing, etc) fit that description, as probably do many of the advanced G codes you mentioned, they probably aren't supported by Mach.
I would also approach Art, the Mach guy, and ask him about doing an affiliate type promotion of the demo version of your software. Since your products are fully complementary, this seems to make sense for both parties. For example, with his download, users could be asked if they would like to try a demo version of your software also. He also generates a fair amount of traffic to his website for downloads, so even if you just had an NCplot download banner there I'm sure it would generate some revenue for you. You would need to of course track these sales and pay an affiliate commission to him, but I'm sure it would be worth it to capture these new sales.
The Tormach company (
www.tormach.com) is another possibility for an affliate type deal to promote sales of NCPlot.
I'm not saying you should focus only on Mach users with the $99. version, but its a nice well defined, reasonably large and easy to access group of users, and if you can have success there you likely will find other user segments to buy the lite version.
One other piece of feedback, the first time I came to your website I was a little put off because the way its worded in some places, ie
"for 4 axis mill and 2 axis lathe Fanuc compatible G-Code programs"
it makes it sound like NCplot is only useful if you have a Fanuc controller, and I wasn't sure NCplot would even work for me. I would recommend rephrasing that to make it clear that NCplot will work with a variety of controllers, not just Fanuc ones.
Another advantage of an entry level priced software version is that once those users become customers you likely will over time be able to convert many of them to upgrade to the full version if you can continue to add features to it to make it attractive. People always want new functionality to play with, and buying it in 2 stages ($99. for the lite version and $198. later on for the upgrade) makes it easier to swallow.
I would consider adding high level conversational programming capability to the "full" version, if that got pretty refined I'd consider popping another $198. to get it on top of a $99. entry level version. The current conversational offerings for Mach are so-so, I think you could make something much better.
Good luck-
Paul Titchener