seems recent posts are following a different track to the OP.
you need to define what your installation will include. The shore connection and incoming protection device/s, including hull earth bonding, is just the 'supply end'.
if there is no existing 240VAC wiring in the boat, then you need to install a ring main with sockets around the boat, or something of that order.
you may also want to install an inverter/charger which gives you the benefit of being able to keep your batteries charged when not using the engine, and of having limited 240VAC when the boat is away from the shore connection.
you need to discuss this with other users so that you can decide what you need, only then can you firm up a budget price.