I believe that point is actually addressed in the FAQ that the article refers to -- the HTML Writer's Guild, as hosts of the mailing list in question, would also become liable to prosecution, and they are in the US. Effectively, therefore, there can be fallout for any party privy to, or enabling, such a conversation, even if the main participants are not under direct US jurisdiction.
So abstaining from discussion of rates here also helps to avoid any actions being brought against VSL or their American business partners.
A further problem is that this is the type of offence where you can be found guilty in your absence (it's a per se federal offence, which means that the facts alone are enough to convict, without any need to get into motives or context, and the burden of proof switches to the defendant to show that their actions were not actually a crime). If you, as defendant, are absent, the conviction stands against you anyway, and any subsequent attempts to enter the US, or even conduct business there from outside, could be seriously hampered for a long time.
I believe there are only four legitimate ways to get the information the original poster wanted: negotiate individually with your customers; adjust your prices, and see what effect it has on your business; use standard rates, based on surveys published by reputable trade or professional bodies; and read an independent survey of what typical rates are, conducted by a journalist not in the line of business, and published somewhere where customers are as likely to see it as suppliers.
Note that I am not a lawyer, and this is not legal advice. [:)]