x2 on the No. There are probably a handful of authentic Cuban Cigars floating around Jamaica, but I think it's safe to say 98% of what you find in any shop there is going to be fake.
There was one shop that I thought had legit cigars there, but a few years ago I stopped by there again and they had a few EL's that I know don't exist.
It's tough too, because last time I went through that airport the duty free cigar vendor there had all kinds of very hard to find cigars (like millenium jars) that may have been real, but it's not worth the risk.