I can offer two real-world factual data points made without judgment:
1. Concerning the argument about people not being able to afford software as a reason for piracy:
In Profound Effects piracy from Russia and China was so rampant that I publicized an offer of "If you are purchasing from any email address from .cn or .ru you can have the product for $1."
Not a single sale was made.
2. Concerning the argument about piracy not having a real effect on companies.
Profound Effects is no longer in business.
were the product one that was marketed extensively in the chinese and russian markets and relying on those sources?
Its obvious that piracy has an effect on sales, whether software, movies or music. However, its not all that obvious what this effect is.
If people stealing it are guilty of bringing down businesses, how can things survive that are given away on a donation basis?
There's more than a few webcomics f.x. that create art on a daily basis.. and had enough donations come in to make it a living, despite not selling a single thing.
The humble indie bundle of games has made 1.2 million so far, and still counting.
Radioheads "pay what you want" album reached 3 million sales despite being basically given away for whatever people wanted to pay.