What if the bitcoin seller is wrong?
It is just an example to illustrate that there are people who can abuse the system of free market for their own personal benefit.
The question is also if this can still be called a free market. If the buyer knew what the seller knew, would he still have bought? And if not, then was it really a voluntary exchange in the first place?
You propose that if i slip a poison into your drink and make you drink it yourself then we should call it suicide because you drank the poison 'voluntarily'. See what kind of problems this word can give?
I sell you sub-prim mortgage instruments that are completely hopeless. But you don't know and gobble them up like cookies.
It was a 'voluntary' exchange. Now you go belly up from all the cookies. Was that what you would call a voluntary exchange?
For a large part it is something that just keeps the population busy enough to not want to revolt or pillage the neighbours etc.
It's a carrot that uses human greed to get people on the slippery slope of career making and loan taking.
And i think its only ethical to provide a save place for people who do not want to compete against such a circus.
Minimum wage is incredibly important in this role. It's a very stabilizing factor in a society. If you can ensure that everyone with a job can buy food and some other necessities from that salary then overall standard of living will increase which increases productivity etc. Overall you'll have a happier society. And i think that is a much 'gooder' goal than profit.
The fact that an employer can excert enourmous power over his workers through wage is another thing that justifies tools like minimum wage. Look at what is going on in and around India where human rights standards are upheld less well. You see frequent abuse of workers by employers. It's because it's a position of power. Without some rules and some power to uphold them this is what you get when you make your markets free. Only you propose it on global industrial scale.
Honestly, there are many many others.
Most of these try to squeeze between the rules. Imagine there were no rules and they had free reighn in their dealings.We would be sooo screwed. Imagine a Monsanto not having to keep to regulations. Imagine a Shell that would have very little insentive to clean up their shit. Imagine an Bell was still one company ruling over their netherpeoples.
Corporate etities can become enourmous and can have little insentive to do something good for society. In fact, they've been known to suck economies dry with no thought of the people living in that region. You can wait till the 'market' corrects itself but by that time maybe many thousands of people would have lost their home. That is not something most people want so we have regulations that prevent certain dangers that markets can pose to society.