[smsm42]

>>> can materially affect the negotiation in a way that is patently not fair.

Here you have to define what "fair" means. One of the definitions would be using extra-market coercion to influence the price - see unions example - is not fair, since it uses forceful coercion to benefit one side. However, unions often claim they need the coercion to reach "fair" prices since otherwise it is "unfair". So what is "fair" here? How you find out if voluntary agreement of two people is "fair" or not?

>>>> we have to destroy capitalism and abolish wage slavery.

Since the only other alternative that we've seen so far is non-wage slavery (at least until we find enough people that agree to work for free that we can create non-scarcity economy) this makes this definition of "fair" rather unappealing. The problem here is that voluntary structures tend to become markets, and calling non-voluntary arrangements "fair" has to rely on notion of fairness of those who apply coercion to support the non-voluntary nature, which very soon devolves into very peculiar understanding of "fairness".