For example a nice improvement could be in Station Dock Control
if you could ask of the docked pilots whether his ship is for sale. In this way even if you see a wanted ship in the space flying towards a station you can follow it then talk with the pilot in the station.
That is a good idea - anything which can provide potential non-violent interactions with NPCs is worth considering!
Another approach might be to let the player put down a deposit on a ship. The ship is then held in that shipyard for a set period of time (perhaps based on the amount put down - a bigger deposit buys you more time?). If the player fails to make it back in time with the rest of the cash, though, then they lose (some? all of?) their deposit. Cancelling the sale before the time limit could be possible, but would have to be done in person (i.e. at that specific shipyard), and would still cost the player a percentage of the original deposit.
All that sounds easy in my head … now someone just needs to code it up, and we're golden!