Every now and then a thread comes up that talks about pirating/buying robot software. I just saw this article today that talks about pirated games thats relevant:http://jeff-vogel.blogspot.com/2010/07/sometimes-its-ok-to-steal-my-games.html
My opinion over the last few years agrees with this guy. Don't pay for software because its 'right' or 'moral' - those terms are ambiguous and undefined. Buy it because you want to encourage the company that made you really neat software to make you more really neat software.
For example, lets say company X makes a really neat robot design program that makes your robot making life much easier. And lets say no one pays for it. Well, the company fails, obviously. But what if everyone paid for it (vs pirating it). Well, the company now has money to grow, and a financial incentive to develop another future program that again makes your robot making life more enjoyable.
Basically, your $50 or whatever is an investment - and a 'thank you'.
Now, I'm not asking you poor college students to cough up $20k for CFD software, thats just silly. But hey, if you do the 'wrong' thing and pirate it, at least you can teach potential customers how to use it, give away free examples to help others use it, and advertise it on your website . . . and if one day you find yourself working for the US Navy and making robot fish, well, you buy it with US taxpayer dollars