Ah - the english word "deception", as opposed to the precise legal term "deception".
Now, in law, I think that (and correct me if I am wrong) that a deception is defined as representing something as true whilst knowing that it is in fact untrue.
On that point, it would appear that the tactic of saying "the item I am selling you is an illegal fake" would absolve them of the charge of deception.
The other aspect is presenting a headline declaring an item to be some brand "For sale ACME unit xxxx" and then in the detail revealing that it is not "This is a WIDGETCO yyyy".
Is that a deception, or is declaring it as a fake at any point a get-out?
Regardless of the above, the item itself is still a fake.
Which infringes trademark & copyright law.