The local nominally owns the boat, despite just having a verbal contract with the previous owner, so would be liable for the cost of removing the boat. But he's a local, and since he's not answering any queries, I'm sure he's lawyered up and will contest the verbal contract. The original owner is gone. So, the government will need to locate him, prove in court that he is the actual owner, and then extract the money or have to pay the salvage costs itself. The first is unlikely to happen. The Beacon Hill wreck is owned by a company which then went bankrupt so there's no money there. The owners are still quite affluent and evidently did not bother with the costs incurred by having insurance.

I think that the 10K$ cost is for marine salvage. The wreck is on the beach close to excellent road access for a truck and crane so I would think that it might be done for less (if a private person were paying, if the government is paying the estimates will of course be much higher)