for an interesting lesson in the real world of connected double dealing, and how governments do what they do, when they might be seen as having devolved into dictatorships, do a search on

'soy bean dollar Argentina' and find some interesting information about exchange rates (for just a few weeks under special authority).

when you want a better rate in Buenos Aires you go to the correct place and listen to hear barkers calling out 'cambia!'.

'Cambia' doesn't mean just to exchange money. It also is sometimes used to mean other types of change.

but some things don't ever seem to change, especially in Argentina..

Cambia!!