Actually a market is a place to negotiate prices. Seller-fixed prices are an American curiosity.

The act of negotiation itself is a cost/fee that people would rather avoid - and for small purchases the need to negotiate is more costly than the actual product price.

Lack of negotiation isn't a curiosity, it reduces friction of transactions - see item, point at it, give the money, you're done; which saves effort for both parties.

Fair enough. But even in negotiated transactions, the seller sets the final price that they will or won't accept.

In a fixed market the fixed price still remains the upper bound for the negotiation. [Until there are more demands outside of the predetermined terms]

Exactly like the buyer.

only in a "free-"market. Also there is a concept of "fair price" for a reason. You can't charge insane prices everywhere, especially for essential items.

It's a good thing a service to help individuals sell their music on a variety of online services isn't essential.

It might be, if making music is the only real way you have to make money. Of course, in that case I would hope that you would use your proceeds to pay the service pretty quickly.

Essentials for Life: food, water, shelter, and cheap access to internet services created by other people.

Wait so if the only real way I made money was by theft, then that would make it "essential"?

Yes, that's is clearly exactly what I said.

Sure, I agree. Not all markets meet the concept of 'free'. But distrokid is competing in a market that is pretty close (helping musicians distribute music to services).