I wanted to buy it yesterday when it was available, but had 20 gold less.
I played today got another 50 gold, BUT … surprise … “Power Core” not available any more.
The people with the ready money had bought it 12 hours ago and I cannot buy it now !
Why ?
Because selling Power Core was probably a mistake and not an intended sell. Celestalon posted on Twitter a short list about their card back philosophy:
"Still available in-game somehow, like adventures? No.
Seasonal? Yes.
Hearthstone pre-purchase or other bundles? Yes.
Cross-game promotions? No.
High-skill based (Legend, Golden Celebration)? No.
Live events? Depends how wide-spread available they were. BlizzCon is a No."
Well, the Power Core cardback got rewarded for just attending certain e-sports events if I’m correct, not for reaching high ranks in these events.
So yeah I don’t get it why they added it and then just removed it within <24 h. I saw it yesterday but wanted to buy it today (god knows why I just didn’t buy it immediately). Maybe it’s because I really didn’t think that they would remove it immediately.
Just another silent action move from Blizzard,. we shouldn’t be surprised, but I surely think a lot of people are mad about that.
I, for one, am just sad that I didn’t grab it yesterday and disappointed that they removed it so fast without a word.
because it was added as purchaseable by accident and when it was discovered it was removed? not everyone is out to get you, you know
May be it was intended otherwise, … but If Someone took advantage of the mistake (in the 12 hours availability) the card removal fix is not fair to all the others (like me).
The fast people now have a “very very rare” item now … and because of a 20 lucking gold I am having only the bad feeling I am … treated bad : )
I still haven’t seen any card backs in the shop since yesterday’s release, is it something only visible when you meet certain conditions?
I kept checking all day yesterday but never saw card backs or heroes
The “Power Cord” cardback is back in the shop 
I just bought it!
Thank you !
Thank you so much! I really appreciate you answering me so quickly!
He/ she is right, i just bought it, too. 
Wtf, this “card back for gold” situation is hilrious!
first: people wants cardback to be available, while others want them to remain exclusive.
then: the second ones are mad because they are available for gold
but, plot twist: the “rare cardback” got removed from the shop. Justice is done.
Plot twist of the plot twist: they are back because… who knows?
Next, on season 2: selling old adventures for gold (nah I am joking; I admit this would be too much for blizzard…)
I was never able to get the Tespa card back. I graduated from college long before this game came out. The same applies to the golden celebration card back. I’m not in China. They might as well just hide those card backs from the client because they are impossible to get.
Sadly here happened a lot of bad management. The first implementation of Power Core was probably a mistake. So they removed it very fast. After this I guess there were some discussions. In the end the opinion won: “Some people allready got Power Core for gold, so let us add him in shop permanently.”
But this decission is bad in many ways. First of all: The so called “esport” card back is not special anymore. With their action they transformed it just to normal card back. Nobody who met this card back on ladder will feel anything anymore. Also bad emotions against opponent possible, like: “What a sweet wannabe, not able to achive a true esport cardback, so now he got this one.”
Second problem: Have anybody thougt about people who truely earned this card back? I speak about true esport players. Must feel terrible for them to see one of their most beautfiul special card backs means nothing anymore. There are tons of card backs. Every month we get a new one. There is no point destroying esport players their achievment.
Powercore shouldn’t be part of the shop. Say open you did a mistake, remove it from non esport players accounts and give them their 600 gold back. They only got it because of an accident and the following actions. Then it would be a special reward just for esport players again.
don’t worry, many players already don’t feel anything when they see a card back; probably they also have no idea how that card back is obtained; many probably don’t even look at the opponent’s card back.
The only people who think this are the ones who give value to a card back.
So I think that those who already got the e-sport card back in the original version will be mad at each other because they think the other player didn’t get it in a legit way.
True, but I think that in this case the requirement was “attend an e-sport event, even as just a viewer”, not the “become GM” or something similar