But despite his stature as a global icon, and intense interest in his well-being, money has failed to follow the flow of interest. Over the past two weeks, as Mandela recuperated in a Pretoria hospital from a recurring lung infection, those trading on his name, directly and indirectly, did not see a spike in their revenues, sometimes to their considerable distress.

In the Pretoria CBD, street vendors flogging portraits and postcards said they had had more inquiries from foreigners, but that sales were occasional at best. In Soweto, at the Regina Mundi church, mosaics with Mandela's name and T-shirts bearing his face sat unsold; vendors said their trade was more heavily influenced by the seasons and weather than by news of the statesman's health.

In the market of rare coins and common medallions nothing much changed, except marked disappointment for traders and speculators still hoping to cash in on common coins.

"In the past there has been a sort of an uptick, but this time we haven't noticed that," says Alan Demby, chief executive of the South African Gold Coin Exchange, which sells a number of Mandela-themed medallions. "Interest in this kind of thing peaks when people are in the news; when British royals Kate and William got engaged, a lot of people bought coins. When they married, more people bought coins. People like to have that kind of memorabilia. With Mandela, it's not always the case."

In 2008 it was indeed the case. Very rare proofs – the most highly valued grade of coin – featuring Mandela achieved record-breaking prices, with confirmed sales of more than R100000 and claims of one coin selling for R2.5-million. After that, various sellers attempted to flog common versions of the same coin for far more than their face value, and often succeeded, with prime examples selling for about R5 000 each.

In July attempts to sell similar coins for R250 each failed dismally, although sealed and allegedly uncirculated coins were sold for R75 a piece. Coins that were actually used as currency, with all the wear and tear that comes with use, were also on offer. An attempt to sell an entire bag of such coins attracted attention – with an offer of R4 each for coins that merchants are obliged to exchange for R5 worth of goods.

The market for Mandela medallions in precious metals, including some issued by Norway and the United States, was somewhat healthier, but still reminiscent of the experiences of street vendors at various tourist destinations: neither price nor volume showed much change during pervasive media coverage of Mandela's health.

"You don't always know with these things," said Demby. "You may ­suddenly see a healthy secondary market, or there could be more ­sellers than buyers if people think they can cash in."