Yes, price controls often do a "good" job of causing shortages. So, an alternative market appears to fill the need.

It isn't that uncommon in countries with relatively high rate of inflation. For example in Ukraine government set some strict monetary controls and it's not really possible to get USD in cash form from official exchanges.

All currency dealers are "black market" [1] -- the only difference is that in some countries, there's a "white market" that bears no resemblance to reality.

Come to think of it, that's true of all "black markets". The only thing that makes a market "black" is the existence of some ridiculous official alternative.

[1] For example: when I land in Japan, I don't get Yen from the JCB -- I get it from a private entity who sells it to me for dollars, usually at a worse than officially stated exchange rate. The Travelex booth at the airport is literally a private market for cash. When I swipe my credit card in a foreign country, the intermediary banks are more than happy to sell me currency, on the spot, for a small fee.

This is very common in the developing world. As governments print money and cause high inflation they want to prevent, or at least significantly delay, citizens exchanging it for a more stable option. So, the governments add friction (limits, KYC equivalents or outright bans) and offer exchanges with less friction at a much lower rate.

Check Argentina -- their "blue rate", used by hotels and other cash-based businesses on site, is often twice as favorable as the official rate that you get with plastic.

That's what they're called, but typically they're the only real and free market and thus have real prices.

If a black market exists, that means the "official" markets are corrupt.

Argentina is littered with them. Walk down Florida Street (ironically named) in Buenos Aires and hear "cambio, cambio, cambio" being yelled out constantly.

Fascinating,but understandable - I was born in ex-Yugoslavia and went through the civil war there so there are many things I take for fully granted that my (Canadian born) wife cannot imagine, from try hyperinflation to various black markets, bribery and corruption :)