Several cards were nerfed recently as part of the fastest balance change in Hearthstone history, targeting Shaman's early dominance in Descent of Dragons. As with all card nerfs, full dust refunds are available for these cards for a limited time - and that time is almost over! If you're planning on profiting, make sure you disenchant the cards before January 2nd.

As a reminder, here's the relevant section of the patch notes detailing the card nerfs.

Quote From Blizzard

Hey everyone!

The 16.0.5 balance update for Hearthstone will be going live tomorrow. Below are the included changes, and as always, we’ll be evaluating the results of these changes over the coming weeks and look forward to your feedback!

Corrupt Elementalist

  • Now costs 6 Mana (up from 5).

Sludge Slurper

  • Now has 1 Attack (down from 2).

Faceless Corruptor

  • Now has 4 Attack (down from 5).

Mogu Fleshshaper

  • Now costs 9 Mana (up from 7).

Once these changes are live, players will be able to disenchant the adjusted cards for their full Arcane Dust value for two weeks.