I don’t think there is any way to test it beforehand, sadly. I wish Ralf would release a test version with limited functionality – it would boost the popularity of this brilliant tool.
The fact that it is the best at what it does (turning a huge list of PC games into semiVR) and the completely new and much better way to play them – it should be a no-brainer to pay even double or triple the current price without second thought.
AFAIK, the program is tied to your hardware/installation, so you can’t just give it to someone else. IMO this is the most negative thing about VorpX – as soon as you have a new install/system, you need to register online again and get a new key. That means that if VorpX is discontiued (like with TriDef) you lose it as soon as you change to a new computer, or even reinstall Windows. :-(
I can tell you $30 is not a lot for vorpX and many ppl spend $60 or more on a whim for the new Call of Duty so…
There’s no demo but anybody who has purchased it will tell you $30 is cheaper than what it should really cost, the only way it would be a bad purchase would be if you didn’t know anything about pc gaming and only out of ignorance in using the software, which all bad reviews i’ve ever read amount to.