As a point of clarification,
www.yugioh-card.com is where the official rulings are posted. But that isn't going to make a bit if difference in this case, since Netrepâ„¢ is a mirror image of all rulings posted. It's just that the official site can't be searched like
netrep.net can, which is kind of the point of why Netrepâ„¢ exists and is so widely used along with the RONIN software. So if any ruling on Netrepâ„¢ is vague, it would be because the official ruling is written the exact same way.
However, that said, the official rulings do say this:
If you draw for "Mirage of Nightmare" during your opponent's Standby Phase, and then activate "Imperial Order" after that, during your Standby Phase you will have 2 mandatory effects: discarding for "Mirage of Nightmare" and paying 700 Life Points for "Imperial Order" or else destroying it. In this case, you choose which effect to resolve first, and you can choose to resolve "Mirage of Nightmare" first, even though its effect will be negated by "Imperial Order". So you activate its effect, and do not discard. Then you can choose not to pay 700 Life Points to keep "Imperial Order", and "Imperial Order" will be destroyed. Then you can enter Main Phase 1, and you did not have to discard for "Mirage of Nightmare" (because its effect was negated at the time you chose to resolve it).
Which shows that the discard is an effect that can be negated by Imperial Order and not a cost. Costs will never be referred to as effects in the rulings. And costs can't be negated by negation effects. Plus, costs will either happen before the activation of card
(as payment for the effect) or it will occur as a form of maintenance,
(in other words, you have to make the payment to keep the card active e.g. Imperial Order, Messenger of Peace, etc.) so a cost wouldn't be something that occurs at the resolution or end of an effect.
