I'm a massive guitar whore, so consider the following a public service announcement.

Gibson are one of the biggest names in guitars. They are also quite expensive. Little wonder then that a massive counterfeit market has emerged. So your buying a new Les Paul, but have never had the opportunity to play the real thing before. How do you tell whether or not the guitar you are holding in your hands is the real deal or not?

For one, do the research. Learn how to identify fake Gibson guitars.

Second, consider the price. Does it seem too good to be true? If it seems too good to be true, then it almost certainly is.

One other piece of advice, never buy an instrument sight unseen.  And finally, if in doubt, ask an expert.