A scenario:
I send U$D1,000 from my US bank account to myself through WU, go to a branch in BA and they give me $83,200 pesos.
Then I walk over to an 'oficial' exchange office, and turn my $83,200 pesos into U$D1,434.
Could I then go to a cueva and use the blue rate sell dollars for pesos, and just keep flipping the money over and over? What am I missing here?