Do I need to declare new (still in package) pc parts when arriving at airport in SA? Or any country in general?

Do I need to declare new (still in package) pc parts when arriving at airport in SA? Or any country in general?

That depends on the type of parts, the price associated and the individual customs laws of the respective country. In general new stuff is probably more critical because it might be used for commercial purposes

It's a shame that people in an appropriate section, such as Business & Finance, will never see this question.

Otherwise, take the parts for a ride on the 7 Train.

YES you declare EVERYTHING you have with you to the Customs officer when you enter a country. There may or may not be a fee to import the item.
Hiding it and having it discovered can result in seizure, a fine, jail time and expulsion from the country.
They could just turn you around and send you back while they keep your hidden items.

When you return to your own country, anything you bought outside the country (that you didn't have with you when you left), needs to be declared.

When you visit another country, anything that you plan to sell there or give to someone there needs to be declared. Personal electronics (cell phone, etc.) that you brought from home and plan to bring back home with you usually don't need to be declared, but this may not be true of all countries. Because they are still in the package, so it "looks" like you might be planning to sell them, and it is obvious that you haven't started using them, I think it's more likely to cause a problem that things that you are bringing just to use while traveling.