This is a linear regression relying on a couple years of data to predict 15 years in the future and I don't believe that the valuation is made on this basis.

It may be that spaceX is buying an operation that would realistically take 5 months and 100 million to copy in-house for 60B because the worry is that waiting 5 months might cost that much in some sort of lost opportunity. It also might be that in any negotiation SpaceX is viewed as incredibly cash-rich and so anything can be sold to them for inflated prices.

I really don't understand these companies valuations it seems like boardrooms everywhere are in a constant state of panic that they'll lose it all if they aren't growing a breakneck pace constantly.