Speaking strictly about ISOM,s, I don't think there would be much difference between Brand tobacco and street stuff. The temprature is the deciding factor. The eggs are microscopic and fumigation is done in the barns across the board. You'd be surprised how many of those "fake" cigars come out of the same barns as the brand cigars. These tobacco are basically stolen/sold either from the factory or the farms itself, given that they came out of Cuba.
Having said all that, I would not take a chance of ruining my prized cigars on a count of a 50 cent cigar. It would be like blasphemy. All it takes is one stick to ruin a whole batch.