A silly question. Whatever the case may be, I wouldn’t worry about it.
If a student registers your website in 30 directories for 100 CZK and adds original descriptions, there’s nothing to worry about. Just send them the money. They get beer money and you have the assurance that you haven’t overlooked anything.
Usually, the student’s price is around 1-2 CZK per directory. Don’t worry about that, send them twice as much and you’ll see their enthusiasm for the work.