To be fair, it's not really the bricks that are so expensive. It's the dirt :)
The bricks add another $250k, which is why the used houses go for somewhat less.
Like when they built The Dakota.
Saves somewhat on the materials, but a lot of the cost is labor and things like plumbing, electrical, etc.
Are these gold plated? That seems absurdly high.
Also you maybe be underestimating how expensive bricks are! A brick house might have 10k bricks and fancy ones can cost like £2 each, so that's £20k literally just on the materials for the outer skin.
House construction is expensive because it uses a ton of materials (even if per kg the material is cheap) and a ton of labour.
But whatever the materials, you're looking at a minimum of $100k for materials, and then the rest is labor and other expenses (like delivery, excavation, etc).
Even a "manufactured home" (think: doublewide) costs something like $80-$100k before delivery these days.