Yes on the "duty-free" status of computers and books.
Remember though, "duty-free" does not mean "tax-free".
You will still need to pay 12.5% sales tax on the computer and on the cost of shipping. There may be an environmental tax as well (not sure on that - if so, it is around 2%).
Laptops are frequently carried in by travelers as part of their personal gear and as such they usually don't get taxed at all. Of course this would mean that you are bringing only one, it's not still in the box and it's really yours.