That's your best bet then. yes it is a common practice for sellers to ship at a reduced invoice value to avoid heavy duties, i would tell you to tell the laptop company to give the laptop invoice at around 400$(not too low nor too high), so it's believable. If they asks you to pay customs , it'll be less than a 100$ which is a bargain considering the actual shipment value. But as a thumb rule if the shipment value is way too low they don't charge you duty but i wouldn't risk that with a shiny new 1800$ laptop. I would just say it's for 400$, i sent it with a friend for repair and the compnay agreed to ship it back directly to you since the invoice and address is in your name.