Propaganda

• WWizards of the Coast2004-10-04
  Official Ruling
  If there is more than one Propaganda on the battlefield, the cost is cumulative.
• WWizards of the Coast2004-10-04
  Official Ruling
  If there are multiple attacks in a turn, then you have to pay for each attack.
• WWizards of the Coast2004-10-04
  Official Ruling
  The payment is made during the declare attackers step at the same time you are declaring the attacker.
• WWizards of the Coast2004-10-04
  Official Ruling
  Paying this cost is not an instant or any other kind of ability, it is an additional cost on the declaration of the attacker.

Rulings via Scryfall