Brazilian visitors gawk in wonder as they stroll past shop windows along touristy Florida street in the Argentine capital of Buenos Aires. The jackets, the shoes — they're all so cheap when your purse is stuffed with black-market money.

Visitors who turn to the streets rather than the banks to swap their dollars in Argentina are getting a bonanza of extra pesos and can shop much more cheaply than back at home. A leather jacket that costs $250 in Lima, Peru, can be had for about $150 in Buenos Aires.

That's causing a flood of day-trippers and other visitors from neighboring countries into Argentina, which keeps tightening its currency controls in hopes of protecting foreign reserves and reducing the flight of dollars.