You gotta be careful when purchasing Cubanos. Real bands, and real boxes does not necesarly mean real cigars, specially in Mexico!! LOL
I would pay attention to the cigar, depending on what you are buying. Look at the box as a whole, are all the cigars the same? Do they all look familiar, look at the caps, are they 3ple, pig tail, etc....
But even then, I have seen some real good counterfits, like I always say, the real test is in the smoking. To be on the safer side anytime you go into a foreign country and try to purchase from the dark side, allways go to an authorized retailer. Stay away from tourist shops, coffe shops and hotel shops, unless ofcoarse this are authorizes Habanos retailer!!