Thank SpaceX for slashing launch costs and me for not factoring in much of a second stage to boost that mass out of orbit.
But I was also extremely generous with the thickness in the first post. In real life they would almost certainly be closer to .05mm than 1.2mm, and probably not made out of solid gold.
The point was to show that even with some rather pessimistic assumptions the project was within human scale and even had some precedent.
