One thing that doesn't seem to be made quite explicit: Are portal jumps one system at a time? So that you renew your roll/payment/calculations for every stop on your route to a distant system?
Or do you calculate/pay/roll once for an entire trip with several intermediate stops?
Another way of putting it: From Menkar, you can only jump to Daybul? Whereas from Kua, you can reach Aiwaz, Altai, Hamura and Caph (but only those with one jump)?
It seems overly restrictive to jump one stop at a time, but perhaps too 'cheap' to reach any-from-any (and why the chained routes then?).
I'm thinking of house-ruling this unless anyone has a definitive answer with rules refs.
Hope I've missed something obvious!
"Some stars have more than one portal, each one leading to a different system."
"When a ship passes through a portal, it is instantly transported to the next.
Each field links two star systems together and jumps can be made both ways, simultaneously and without risk of collision."
Following that then you will have to prepare, pay and roll for each jump. You can also wait for other ships/join a convoy to split the cost: