Yes there are a lot of "false" Corso that some backyard breeder mixed with pitbull, terrier, mastiff, to appear to be a Corso but are not.
You will pay for quality. Temperament is the #1 trait I would look for in a "Cane". Most want or think that they will get aggressive that's not what the breed was meant for, but they have no issue with protecting it's master and property.
I was once personal friends with Dr. Carl Semencic, the author of many authoritative books on dogs and dog breed history. When, about twenty years ago, I told him I was considering a Cane Corso, he informed me that the actual breed doesn't any longer exist. All that's left is a recreation of the original breed.
That's not to say they're not great dogs.
