I obviously don't know the person that sells them to you, but it does beg the question, if someone is perfectly happy to break the law, I'd think twice about what ever they tell me.... :0)
I understand this is an emotive subject, but I find it hard to find any justification for an illegal trade.
It's not impossible to buy genuine. There's many a time over the years I've had to save, over what seems huuuggggeee lengths of time to purchase something fab, and at the end of the wait, it somehow makes the purchase even more exciting! And there is also the opportunity to purchase during sales, or from genuine outlet stores.
As I said, just my thoughts, so no offence intended.
K