I actually tend to view it as $20 less than the professional version of Fusion ($99). :) Hehe. But, yes, the provider works with the trial, regular, and professional versions, so you can argue it is $30 more.

The reason is that VMware Fusion is woefully underpriced on Mac OS X systems, due to steep competition from Parallels. The equivalent on Windows is $249.

My argument is that the value you get out of something like Vagrant + VMware Fusion pays for itself in less than an hour per seat (assuming you're billing more than $79/hour). I find that to be pretty good value, rather than comparing it directly to VMware Fusion.