What about Solgaleo-GX?, the price went down like 8 dollars after the tin release.
Would the cost of darkrai ex go down? That would be pretty cool
I'd think there are a few variables to consider for the price drop:
Is it both easier and cheaper to get the version in the tin?
Usually, it is easier to get them in the tin, but... not always cheaper.
For example, the tins probably won't lower Rayquaza's and Mewtwo's prices, because the singles are significantly cheaper.
Which artwork do players find most attractive? Does the card have different rarities/versions already printed?
Different prints mean different implied values.
For example, the normal artwork may drop in price, but the FA may stay the same; because it is still rare.
But, if the promo has "better" artwork, this could also contribute to the price dropping.
Is the card competitively viable? Is it the main attacker, or a supporting card?
Darkrai is the main attacker for his deck, meaning, you will be needing 3-4 copies of the card.
The more copies you need, the more you have to pay the difference.
For Solgaleo, you only need 2 copies, so the impact of the price difference is less severe.
4 Darkrais at $13.49 = $53.96
4 Tins at $19.99 = $79.96
Is the $26 difference enough to deter customer's from the product...? That's for the players to decide.
Something else to consider:
Promo cards usually have a bend, due to poor packaging standards. For this reason, I prefer getting the singles.
(Image link is of a Salamence collection I opened)
In conclusion:
I'm not expecting a significant drop in Darkrai's price, but I'd understand if it dropped a couple bucks.
Only time will tell~