At this point, a hard $50 floor would have value for the producers - it guarantees them a minimum (and already pretty high) level of income, and thus predictability in their budget, which would allow them to make nice promises to their population and actually fulfill them. And guaranteeing a floor does not precluse higher prices.
And of course, Chavez is making this offer safe in the knowledge that it will never be accepted by the West, so his "generosity" costs him nothing. In the long run, we're all dead. John Maynard Keynes