Shipyards are great... but I'd like to have a station which people can visit and buy ships from as well (perhaps have the shipyard computer linked to a store module). Set a fixed price for a ship, and, assuming there's enough parts in stock, offer other players the ability to buy a ship from a station. This ship will be constructed as belonging to the player that bought the ship. The only other players that can remove a ship that has been constructed in such a shipyard would be store owners and those that have edit permission on the structure.