>Exploitation is a value-laden characterization, its not an objective feature of a relationship.

We can think of what characterizes exploitation using what we already know and our intuitions of what is and isn't exploitative. If a relationship fulfills those characteristics, we can say it's an exploitative relationship.

>Aside from that, markets are an efficient method of allocating scarce resources

This may be true, but there's no reason to think it's the most efficient, nor is there reason to think efficiency is the only goal that an economy (built for and by humans for human ends) should have.

>Because the market is a means for allocating scarce resources and unrestricted market transactions are Pareto improvements.

I don't care about Pareto improvements, I asked about justice. No philosopher (or anyone, really) defines justice with only the idea of goods allocation or Pareto improvement in mind.

>Because the market is not a thing-in-itself but a label we give to the collective actions of market participants

This is tautological; the market is ... actions of market participants. You outlined my entitlement in the market but didn't make a case as to why the market should manage such entitlements for everyone, especially under the fact that it is nigh-impossible to abstain from the market (or taxes, take your pick).

Besides this, I don't really buy the idea that the market is simply "collective actions" - a space in which to create those actions must be made with private property laws and the protection of that property. Resources must be accumulated, sometimes by colonization. People and must be brought into the market, by force if necessary, by enclosure. The collective actions of buying, selling, and valuing are taught by other market participants to children. It's an institution, and one which (in its global form) highly historically specific - and just as goods are made by people, not handed like mana from heaven, markets were too, and our collective actions reproduce those market relations. Should those relations not be reproduced in a country for but a week, its market would collapse. I think this paper says it best:

"Hayek’s observations on the nature of social evolution and spontaneous order are
insightful and profound when used as a descriptive scheme for understanding how
social institutions grow and change, but they do not convert effectively into
normative guides. A wise lawmaker or judge seeking to follow Hayekian prescriptions is left with a vague and contradictory set of precepts. On one hand, it is
unwise to alter long-standing social institutions by implementing rational abstractions of justice, but, on the other, it is necessary to do so because not all social
orders that have spontaneously evolved are just ones. If the lawmaker or judge
acts to alter a social institution, that action may be condemned as rationalistic
constructivism when viewed at close range, but will appear as one experiment
undertaken in the whole process of spontaneous order when viewed as part of
the bustling dynamism of society as a whole. Spontaneous order is therefore in
the eye of the beholder." (https://www.independent.org/pdf/tir/tir_14_01_1_sandefur.pdf)

>Mutually reciprocal norms arise from a desire to avoid violence and a desire for the best deal possible.

That may be true, but it's a historical and anthropological question as to whether this is how capitalism arose, and whether it is practiced in such a way today. Even philosophers sympathetic to libertarianism note the multiplier effect of injustices longer in the past which accrue as present injustices - and right-libertarians typically have no answer as to how to solve this.

>I'll ask you to proceed with this questioning.

I'm unconvinced that a rights-based account is the most just option for society's flourishing and indeed the flourishing of most individuals. I don't think the right to private property or the right to employ waged labourers has a sufficient case made for it, given that it results in widespread exploitation. The plight of the majority of the population needing to sell their labour-time to survive is failed by a rights-based account which can only say "you can employ people too, it's a right, you know!".

>This is a Marxist fallacy which has caused an inestimable amount of sorrow. Individuals have interests, classes do not.

Classes absolutely do have interests, and just as the market may demonstrate that product X sells at price Y through the collective actions of buyers and sellers, those same collective actions and bargaining which pulls like a tug-of-war rope between labour and capital continuously shows itself, whether at Google or in a coal mine or in a new minimum wage law. Society (and by extension classes) produce people and imbue them with position and skills. A child is born into a societal grouping before he or she is even individuated. Individuals have interests - and those are typically a superset containing class interests.

>Yet self-proclaimed Marxists advocate for increasing the minimum wage.

To be in line with Marx they'd do so in a parliamentary system only under the banner of a socialist party - and it's reasonable to think that Marxists tend to support socialist parties.