Maybe I was a bit judgmental. If so, I apologize. We all perceive the world through our life’s experiences and I’ve been part of the Zeitgeist movement for too long to remain completely unbiased. I am very much aware of how a monetary economy works and know how to operate in it. I’m certain there’s still room for improvement (I’m here to learn after all), but I know how it works and I’m okay with that. Nothing is truly free and somewhere somebody always loses. It’s not a zero-sum game.
Obviously my friend was quite well paid for his services, given the fact that he owned a house in at least three countries that I know of (the one in Scotland may actually have met the definition of a castle). If you’d asked him for two months work, he would have definitely charged you an arm and a leg.
But if you had asked him to take a day or even a few days to help produce a video to go with EoG, the only demand he would have made is that you made it freely available on the product page, knowing full well it would likely get you more purchases and him very little (your target demographic and his are quite different). His wallet would not have noticed, he might even have used the excuse to go shopping in wherever you live. He loved flying. Maybe that was the value he got out of it, an excuse to do what he loved: talking, flying and shopping. 
Apparently not conveyed very well, my point was not that making money is morally wrong (I’m even a big supporter of teaching kids badly needed money-literacy at school), but that I would roll my eyes if I saw a millionaire argue with a street vendor to get his one dollar and 13 cents change back. Did you really ask them for weeks of their time, or did you just ask for a little bit more?
The fact that I felt a strong urge to rant if you will was a gut reaction to your report of how you got tons of messages when even just starting to bring it up. As if they wouldn’t even let you finish the question before talking profit. That just got to me. At least let you finish and then calmly negotiate possible terms. In hindsight I suppose that indeed came from my moral center, so once again I offer my apologies.
Side-note: Ever seen this wonderful Paris Hilton clip? Watch what she does with her one dollar and 13 cents.
Back to the topic at hand: are the multi-stage products just as stackable as the “standard” products? Seems to me the multi-stages work better by themselves. Or that some stages stack better compared to other stages.