MacBBQ

What to upgrade next

1. 
   FireballLevel 15 → 16In 4 of your 10 best decks · 0.6 levels below those decks' average
2. 
   FurnaceLevel 15 → 16In 3 of your 10 best decks · 0.7 levels below those decks' average
3. 
   Heal SpiritLevel 15 → 16In 3 of your 10 best decks · 0.7 levels below those decks' average
4. 
   GiantLevel 15 → 16In 3 of your 10 best decks · 0.7 levels below those decks' average
5. 
   Royal GhostLevel 15 → 16In 2 of your 10 best decks · 0.6 levels below those decks' average

Based on the 10 best popular decks you can already play. The API doesn't include gold costs, so this ranks by how much an upgrade helps those decks, not by price.