I got mine for absolutely free.
The only catch that I found was that they did give me some grief over it. I had enough people signed up and they had problems "approving" them. I have no idea what criteria they use. I KNEW these people were real so I sent them a bunch of emails complaining. It took me a few months but suddenly they switched their decision and approved everyone and sent me the iPod.
I've talked to others who had no problem at all getting theirs.
I thought it was definitely worth it. I'd never, ever buy one for myself, I'm way too cheap.
If you think the're screwing you over, contact them through the parent website,
Gratis Internet.