I can buy cards at the library at over twice the cost, but I can't buy from the bazaar and I have just barely 300 cards, and over 200k in gold. I have tried restarting the game and changing realms. Is there a current glitch happening?
Check your backpack. If your backpack is full, you will not be able to buy treasure cards at the bazaar, yet can still buy them at the library.
Hannah, you make a good point. Rebecca, maybe you do buy the cards, but don't see them. Check your spell book. The cards won't be in your deck until you put them in yourself. After you put them in, you can then use them. You can also take out cards, maybe your book is full. I hope that it helps.