If the bounty is on that ship which cannot be cleared by jumping into a sidewinder and self destructing.
Then when they go back into that ship they wont be able to do missions to get credits as they will be blown out of the sky as soon as go into controlled space, be it fed imperial or independent. They will be ganked by full wings of elite NPC's.
They wont be able to dock in anything other than pirate bases, which will only offer maybe smuggling missions to stations controlled by factions, and hence get blown to bits by the station there if they have to rebuy a new ship every time they destroy someone else's ship, then that will get as tedious for them as it will for their Gankee's.
Because when his ship is destroyed by NPC's stations etc you will get back the insurance that you paid out, and it will come from his credits, his mate will get just the bounty on the commander.
If he wants to avoid being blown up by stations/NPC's he will have to conduct his ganking only in anarchy space, and if your going into anarchy space you know what risks you are running.
Anarchy should be dangerous and deadly, safe secs should be safe.
And maybe my thinking is a little wrong.
For sure they could just jump into another ship, and do missions.
SO maybe yeah attach it to the commander.
The important aspect is that when he kills an innocent unwanted pilot the rebuy cost gets logged to that commander, and not to a bounty that gets claimed when he gets killed by one of his mates.
When he does die eventually, he has to pay back from his credits all of the insurance payouts he has directly caused, could maybe bankrupt him force him back into a sidey if he has killed a lot of innocents, and the innocent some time down the road gets his money back, nice little suprise.
It should be either tied to the commander and the ship. If they get blown up in a sidey and did the crime in the FDL. They have a choice to buy back both the impounded FDL and the destroyed Sidey. The cost of getting the FDL back would be the same as if it were a rebuy.
Otherwise dont allow rebuys at all for players who have x number of murders in a given time.