Falcon heavy has never flown SSO, but it's probably over $1500/kg, which is >50x more expensive. Even the most optimistic estimates for a future starship launch cost is at least $100/kg, so it makes no sense to use $30/kg.
The other line items are probably similarly unrealistic since they include their own launch costs as well.
They also spec 300 racks of 500kg each, which is <40% of the weight of the comparable land rack. I doubt the full weight reduction since the racks still need to survive launch force/vibration in addition to fluid/pressure enclosures that land racks don't require. I think it's likely that just about every part of this report has a similarly cooked numbers, and we can just throw the whole thing out.
Because launch costs and density are completely imaginary. The whole thing is predicated on launch vehicles they hope someone builds eventually. They also appear to have profoundly miscalculated their radiation shielding costs and amounts, but I'm not really motivated to calculate that correctly.
