Other Types of Treasure
Starships, vehicles, and other large assets can't be looted as easily as most other forms of treasure. While using these rewards to give the PCs a base of operations can help progress the story, estimating their wealth and allowing PCs to sell them to buy personal treasure can unbalance a game. Thus, starships, buildings, businesses, and other such assets don't cost the PCs credits to purchase and can't be sold for credits— they're a narrative device meant to help you tell a story. Instead, consider allowing PCs to “trade up” these assets into other assets they're interested in or “trade off” these assets for other benefits, such as introductions to important people, access to previously off-limit locations, favors, street cred, fame, notoriety—in short, power or access.
For some groups, this will feel unrealistic, and you'll want to find another solution. While you could adjust the treasure in future encounters to compensate, it's easier and much safer to make the property impossible to sell, either due to legal complications (like licensing laws), due to the poor shape of the property after the battle, or due to the property's iconic status—everyone knows who it belongs to, and that person certainly isn't your players! These complications could just lower the value of the property such that it becomes an appropriate amount of treasure. This approach can make selling these assets feel like off-loading a financially draining property or tricky to sell.
If the PCs acquire an asset that could conceivably make the PCs money, like ownership of a corporation or a hovercab, remind them that such businesses and ventures require investment, upkeep, and attention—often including staff!—and treat these assets like Earning an Income during downtime. Simply ignore the financial minutiae, let the PCs roll to Earn Income (likely as a group, as such assets are usually shared), and incorporate the asset into the narrative during downtime. If you find this boosts the PCs' wealth too high, you can slightly reduce the treasure you give out to compensate. You can use such assets to provide the PCs other tangible benefits that make the effort seem worthwhile, such as access to resources or introductions to allies.