Douglas, discussion such as this involves, by it's nature, disagreement. When you complain that someone is "invalidating" your opinion, you're actually decrying that they are disagreeing and arguing with you. To disagree inherently involves the invalidation of the oposing opinion.
So stop acting like your opinion isn't being respected just because not everyone is agreeing with it.
And no one has ever been banned for voicing their opinion in a clear, concise, lucid, and polite manner, as you have done. So stop walking on egg shells.
As to whether or not Sideshow is making more or less money for using plastic, I really don't give a flying fak. Their profit margin is not my problem or my business. I run my own little business too, and I don't feel I have to justify my profits to anyone. I don't pay for my materials nearly what I charge either.
For my part, I really wish I could afford this, as I'd articulate the HELL out of it. Can you imagine!?!