As a theme buyer / user I want to give my point of view. As a buyer, price is only 1 of the many concerns when choosing a theme. The other most important criteria is support – that is what I will pay for. I would happily pay $199 a year (only $16.50 a month) for someone to look at my problem and figure out a solution.
Personally I find that many ThemeForest authors sorely lack the support that many 100% GPL shops provide. I won’t buy anything with “post in the comments for support”. At the very least you need a support site, at best you should have dedicated email ticketing.
It’s just like buying a car – I won’t buy a car that doesn’t have a dealer where I can go get parts and maintenance. My website is as important if not more important than a car for my business, so SUPPORT IS REALLY IMPORTANT.
For these reasons I won’t download pirate themes. Even more so for complicated themes that have lots of options – pirate theme sites won’t even have a manual. (I’m just guessing how it works on pirate theme sites – I’ve never actually visited one before).
Finally, unlike most people I actually know what the GPL is. And while I don’t always agree with the WordPress Foundation’s policies and decisions, I respect the GPL and what it stands for. I think that for many theme authors on Envato, their themes are their livelihoods. If you make your livelihood off a GPL software, then you should respect it’s principles because it was what enabled you to make your livelihood in the first place. Imagine if you had to pay a fee to become a developer like the iOS developer program. WordPress is free, but theme authors shouldn’t take it for granted. Respect why and how it’s free for you, and practice those same principles in your business.