YES if he declares it or they search him, he'll have to pay VAT and a small surcharge. They search every 4th person nowadays - depends also on time of day and airport.
I disagree. Only if you're breaking into a sheepish sweat walking through customs will you draw suspicion.
As long as your Mac looks like an in-use laptop, like, not in the box. You'll breeze right through most of the time. If they ask any questions, you say it was bought in SA. If they still smell a rat, it probably means you're are a horrible actor, fear the Bible a little too much or have 'Thief' tattoed on your forehead.
In my case I recently paid US$50 to a friend's friend who lives in the states, to receive and forward me a Macbook Pro. Saving me about 30% after Shipping, Tax etc.
This was a high spec computer however, so if you're looking at say ordering an entry level 13" MB your cost difference may end up being negligible.
Unless that is, you or someone can physically carry one into the country.
I also looked into using a Mail Forwarding service in the USA, which costs upwards of $30. But it's not always straight forward to arrange and there's the risk of too many strangers hands.
That all said, the entry level MBP's are currently about R13000, which is not tooo bad all considering. I still wouldn't buy one however, because I've made a Pact with myself never to give Core SA (Apple SA's ghastly distributor) another cent.
Very happy.