Put a synth foods base in somewhere, maybe over stuttgart, that sells a new commodity labelled 'synthpaste'.
Synthpaste would be seperate from the other food commodities, with 'food rations' being low-quality 'real' food, and luxury food being high quality 'real' food.
Have the base sell synthpaste for say, 1 credit 'each', and make the synthpaste stack so 10 units of synthpaste = 1 unit of cargo space.
That way an advanced train could carry 50,000 synthpaste, and it would cost him 50,000 credits to buy that synthpaste.
Then on capital worlds, say new tokyo for example, synthpaste would sell for something like 10 credits 'each'. That 50,000 synthpaste load would make 500,000 credits, or 450,000 credits profit.
Numbers may need to be tweaked a bit, but you get the general idea. It'd make synthfoods a decent trading company and hopefully liven up the RP for the LWB/AFA.
EDIT:
and synth paste, food rations, and luxury food should all have extremely high selling prices (higher than any other base) on planet crete.