Disclaimer : There are a few responsive issues, sorry
Just check the small box to flag a ship as capital, it'll update the upgrade cost.
After giving a small try, you'll quickly see that it costs almost 5 million fleet credits to boost any ship to level 85 (precisely 4,977,240).
For a capital ship it's almost 10 million (9,954,480)
What's more interesting is the way the price rises...
Ships are a little cheaper to upgrade than characters. However the fleet credit income is scarce... Maxing a ship, at the time of writing requires dedication !
Both lines follow the same trend at the beginning : with a break at level 53. Getting a ship to level 60 is relatively easy, going further costs a lot.
Indeed : when the second cost increase happens at level 73 for characters, for ship the second break happens at level 66 !
Compared to characters, it's relatively easier for ships to reach level 55 (with a total cost of 344,850 fleet credits).
Capital ships are more expensive.
Starting at level 75, it's more than 400K credits a level, and increasing quickly.
Better pick the good capital ship, because switching ain't free !!