Selling cards

[Asaghon]

Can someone please explain to me why I can or cannot sell certain cards?

I haven't been playing for very long, so it's hard to get good cards to begin with, let alone good cards that work well together. (lvl 16 atm)
At the moment I have something that starts looking decent with Desert Nomads (Got a decent amount of good Eclipse and Temple Guardians to form something of a cohesive deck). I've been farming the last mission of "The Sons of the Volcano" since it's doesn't require your own deck wich is still far too inconsistent to win anything aside from the boss of Zahal. (Though I have cleared everything upto lvl 14 bosses once)

And recently I got Ogmor lvl 1 as reward from Volcano bosses, looked it up and found its worth a nice amount of crytals. I'm sure it's a good card, tough useless to me since I don't have much Noz cards, or atleast none that are good. But the crystals it would fetch me could buy me 1 or 2 really good cards/characters for my current decent decks.

Unfortunatly, for some idiotic reason this card is not "saleable", eventhough I can see the exact same cards for sale on the marketplace. What the hell is up with that?
As if it isn't hard enough for new players already...

I really like this game, but it seems to do anything in it's power to scare off new players. I even spent some money on it to even get those few good cards and even with that I still mostly get oneshotted in any tournament game

[Pikadusk]

Unfortunately, you can't sell cards you win from adventure mode.