"Unless you can afford to have two or more competing teams solving the same problem, and c’mon, who would do that, you will never know."

So, the above metaphor is almost always impractical, and it's hard to tell what the alternative is to the one bricklayer you have.

The mythical man month never mentioned that. It mentioned multiple implementations of one architecture, but that was for hardware IIRC.

A better example is if A now comes back and says "yes, my wall's not as good, and I take longer, but now I'm only going to charge $4000", then you've got a bigger question - is it worth $1000 to you to get a higher quality wall that's done quicker? Or would you rather save the money and lose the time and build quality?

This more easily converts to a software example - do you pay a senior developer to develop your product quickly and well? Or do you save money by hiring a developer of lower skill, who will likely take longer and deliver a lower-quality product?

What if you have no background in software? If the lower-skill developer convinces you his work is better (even if it's not) you're going to go with him.

I'm more inclined to think that people would try to bargain hard with the Bricklayer B - "$500 in two hours is a good price for you, pal". After all the thought goes that even for that price B can erect a lot of walls in two weeks (which is A's single wall building time-span), and that's... only fair, right?

(in addition) Don't foul yourself that we live only under market-like laws of supply and demand, we're also social creatures that supposedly have to obey social norms. And the norms can be dictated.