Gav
Andy is right you need start fresh with NSW rego and will not get any refund for the remaining Vic reg from the NSW folk. You will have to send the plates to Vic for a refund, less fees
You will also need to pay stamp duty on the purchase price of the car.
So in short, don't pay extra for long Vic rego - ideally you want a car that has just enough Vic rego to get it to NSW.
Good luck mate.