Depends on your time frame. Long term, with this government the currency controls arent going anywhere and I highly doubt before the next Presidential elections (definitely not before elections this year) will they devalue significantly the official (especially seeing as that is what Clarin and a lot of people want). Therefore, in medium term 1-2 years I dont think the gap between the blue and the offical is going to close, blue is only going one way. Venezuela is not a bad guide, devaluation has fixed the offical rate at USD / Bolivars 6.3, whereas the unofficial is 23.
If you need pesos, want to sell dollars in the next couple of months, perhaps, but I am not selling the dollars I have now, no way José.