Anything costing over somewhere around $100 and above is charged 33% at the customs. Could be less depending on whether the product is second hand, outdated and whatever else the customs guys deem necessary.
Of course, it depends on the size of your product. So even if you undervalue the product by removing the price stamp, and packaging, if its a monster graphics card, then you can be sure to pay some good customs duty. But if its as tiny and useless-looking as a cable of sorts, then there might not be any customs.
I'd say you will end up paying around 2-3k on customs.