What is the best way to exchange US dollars to local currency
The best way.. and nothing else comes close.. is to get rand from an ATM with the debit card from your US bank. The exchange rate, using that process, is better than you would get even if you went into a bank to change $USD for ZAR, And infinitely quicker!
I bank at Wells Fargo and they charge me $5 for each withdrawal so I take our a significant amount when I do make a withdrawal. Like R3000. Which would be $230 - $240.