These modern bi-metallic coins with the cool bust of Nelson Mandela and the national arms of South Africa are worth only face value, unless in absolutely, fully uncirculated condition, where a keen collector might pick it up for around $5 US Dollars.
CHARL, you describe your coin as being slabbed - you might have the proof issue of the coin, which catalogs for about $15 when the coin has not been taken out of the slab and picked up any wear, fingerprints or ugly staining. Proof coins are special coins minted especially for collectors. They often, but not always, carry premiums over and above normal coins struck for business.
As always, read the 'Important Terminology' page found at the top left of the page to understand what the term 'catalog value' means.