forming composit space station skin in situ

Ok, if we consider a 50 m shell, we get 65,449 cubic meters for a total
volume, and for the inside volume of the inner shell, we get 44,602
cubic meters.
Getting it up in one shot is a good goal. But I'm trying to maximize
leasable volume, too. A 100 meter sphere give 523,598 cubic meters of
internal volume, and 434,892 cubic meters inside the inner shell. I
still think the inner and outer shell concept is important for puncture
repair, and sheilding augmentation, and general ease of construction.

The costs are going to be such to develop any sizable facility that we
probably are going to need about 50 tenants, besides the resort/hotel
with about 25 guests per week, (eventually), a large "movie set", a
repair/maintenance /workshack area for contract projects such as a Mars
trip, other larger facilities and so on. I don't think a 50 meter
sphere is going to be big enough. to bring in enough income.