But what you can charge for the services of your ship will also dramatically increase. It's really a matter of coming up with a story about the ship and less the Mechanics I think. I'm hoping we get some good Narrative suggestions on how to integrate a custom ship into the game. Realistically it's not too hard to devise reasons why a group of Rebels would have a custom ship, from testing and experimenting through to sheer necessity and desperation. The point though is that the story provides everything needed so that the PC's can do the fun part.
It would be nice to see that all repeated in an EotE campaign (or corporate sector book) with Edge flavour rather than AoR too. The reasons are definitely different in that instance.
I wouldn't be surprised if the price for materials was also talked about in relation to Contribution Rank cost as well, similar to base upgrades.