You seem to have a handle on this so I was wondering if you could vet my business idea for viability:
Toilet rolls.
After Air, Water and Food it's going to be the thing any ship, space station or moon-base with living people and a toilet can't be without, and I predict there will be a constant need for emergency supply requests considering how unreliable the demand for this resource can be... anything from an explorer ship 3 weeks into a two month cartography mission finding they only have two rolls and a copy of the Encyclopedia Galactica left, to Port Olisar after a dodgy batch of Big Bennys takes its toll on the staff with no supply shipment due until Thursday, any place from inner system to the frontier mining outposts may be struck with the sudden, urgent need for a few SCU of bumwad.
So a fleet of 350R's with the 4 SCU cargo compartment loaded with bog parchment, ready and waiting to fly direct to the disaster area at a moments notice... For the bigger destinations like Olisar a few Connie Taurus with the engines maxed out, flying thousands of feet of paper directly to them in their hour of need... at a premium, of course - it'd be a sellers market.
Once I have made enough to set up my own prediction center I'd be able to grow the wood, process it into paper ensuring quality and value, and ship my own rolls at minimum cost making me even more profit and, hopefully, the games first Bumwad Billionaire.
What do you think? There will undoubtedly be the need for it, but the question is - is it viable?