What is the cost of a stamp from South Africa about 50 to 60 years old with some monarch's image on it?

Question

What is the cost of a stamp from South Africa about 50 to 60 years old with some monarch's image on it?
It has the marking Suid Afrika on it...

Answer 1

Whoa! I'd have to know a lot more about the stamp to say anything meaningful. What is the color? What denomination (face value)? Has it been used? Is it damaged in ANY way? If used, is it still on the original envelope? And that's just for starters.

Bottom line, however, is that most stamps of that vintage (but not all) are worth very little - a few cents. Common stamps stay common; only scarce stamps get valuable with age.