Some good points have been brought up here and I will throw in a couple more. These are just speculation as I really don't have any insight into how Hugo thinks or acts.

However I see this gold sale rule as a way to favour some companies over another. At present exchange rates there is no way to borrow money to build a mine and get paid for 70% of the production at 2.15 bolivars to the dollar. All your interest payments would be in external currency so that alone would kill the economics where your realised price is only 1/3 of the actual world price.

Sure local labour, fuel and taxes would be due in bolivar but if this disparity between the unofficial and official rates persists or widens, then inflation will take off in Venezuela and local costs must rise. Offshore costs for machinery, finance, transport, management, chemicals, spares, refining etc. would simply continue to increase as the unoffical rate for the bolivar deteriorates.

The only saviour would be a permit to convert bolivar to dollars at the official rate, but these permits are handled one at a time and as I see it there is no such thing as a "licence" that allows any company convert curency continually. Any company that Hugo considered was "profiting" at the expense of the country could be bankrupted by simply refusing them permission to convert their bolivars to real money.

Even the airlines are hurting in Venezuela because their requests to convert Bolivar have been sitting around since last October. Hugo and his henchmen can destroy any company they wish where their income is in controlled Bolivar but their outgoings are in a foreign currency simply by forcing them to accept unofficial rates and dropping their gross return to 1/3 of the real price.