The system sucks, but it's the system we have, and it costs money to fight these battles. If you like the result here, consider setting up a recurring donation to the EFF.
http://hitboxteam.com/content/articles/dustforce-sales-figur...
http://hitboxteam.com/dustforce-sales-figures
This isn't an exception, either. This is the norm.
Edit: membership now renewed
It's the "Give % of sales to non-profit of your choice" option in Amazon.
That's the reason I've not started using it. Online stores use all kinds of indicators (user agent, OS, number of searches for similar items, etc) to jack up prices when they think they can get away with it, and I suspect this metric is very relevant in that context.
I just donate to EFF and others directly.