Does for instance the stat destroyer on wave 1 come with different upgrade cards compared to the core set? Or are all the wave 1 ships that I'm the core set the same?
Is it worth buying the same ships again?
Expansion ships usually have things that the core sets don't. A new Admiral (Motti), some new upgrades, and a new ship title to add to your collection.
Plus two victories is a pretty good core for any Imperial List. You could go up with an Imperial (Hopefully) or down with Gladiators/Raiders and a gaggle of fighters.
Cheers, Good to know