I did a little research into this, and evidently there is a legal loophole, using debt/equity swaps, for the Venezuelan financial industry to exchange Bolivars for other currencies without restriction. There are institutions that do this, operating as currency exchanges for companies, and they are the ones that have found the "real" exchange to be 6.5ish. (It used to be lower, but Venezuela has been running up inflation, surprise surprise. Evidently the central bank there is on the verge of being literally out of USD.)

While it would be possible for a foreigner to come in with a big wad of USD (have to evade customs), fastflyer is correct that there's no mechanism to trade the bolivars back at the 2.15 rate. Your only route is to use the debt/equity institutions, which would put you right back at the "black market" exchange rate you used on the street.

What confuses me is how an airline then prices their products in Venezuela. I'm assuming here that an international company operating in Venezuela would want to pull their profits back to their native currency, so they can pay stockholders, etc. If you sell an airline ticket online in USD, you don't need to care. But if you're paid in bolivars at the airport (I take it this is frequently done in Venezuela? Or at least Graraps thinks it's done easily.), you need to exchange that currency. You have a mechanism to do that: the exchange companies.

When a company converts an advertised USD price to a bolivar price to a physically present customer, are they legally required to use a 2.15 conversion rate? If not, I would expect a company being paid bolivars in cash to price their goods much higher in bolivars. This would negate most, though probably not all, of the exchange benefit to the consumer.

So someone help me out with this situation.