Anything that is brought in from overseas is liable for import duties. Sometimes there are (official or unofficial) minimum values under which the duties will be waived, but a new Mac is certainly above those minimum values (which are commonly around $20 or $30).
However, if you bring an item into the country yourself in your own luggage and do not declare it, you may not be asked to pay duty. Technically you are supposed to declare anything over a certain value.
The general rule is that if you use a courier service to ship something, you will almost certainly pay duty on it, but your items will also be insured properly. Using a service like USPS or EMS will give you much less in the way of insurance, but items are not always 'caught' by customs.
The easiest way to get a new Mac would be to buy one where you live. You might need to build-to-order if you don't want the local keyboard, but you will get the computer you want, legally, with all the necessary taxes and duties already paid. If you ship one in from overseas, you will need to pay (very high) shipping costs, and import duties. There is no way of avoiding that unless you fly out and buy it yourself, then carry it with you in your luggage and hope not to get caught at customs.
An alternative (depending where you are) is to buy in Hong Kong, but again I am not sure which default keyboards laptops come with in HK. That's a much shorter flight, and the Apple Store prices are quite reasonable there.
EDIT: If writing "PERSONAL ITEMS" on a package magically meant it could waft through customs without attracting duty, everyone (no, really - everyone) would always do it.