Hearthpwn

General Strategy

This deck is built almost entirely about getting value out of your every card. You have the beefy creatures like Chillwind Yeti and Harvest Golem to trade for hopefully 2 or 3 other creatures. You have the Siphon Soul to heal a bit and get rid of big taunts or other powerful creatures you can't deal with. You have the Wild Pyromancer and many small spells to help you deal with early aggro (And to deal with those pesky token Druids I keep seeing). 

Replacements

Cairne Bloodhoof and Ragnaros the Firelord can be replaced with Boulderfist Ogre if you can't afford them. You lose a bit of value, but Big Game Hunter won't be able to instantly destroy your most powerful card, and you'll save 3200 dust. Halves the deck's cost right there.

Odd cards

There's a few cards here that look strange, and I have my reasons for them being in there, although you might prefer changing them around to fit the meta, or you might just dislike them. 

Stampeding Kodo is a solid card that can kill some pretty powerful cards (Including, but not limited to, Keeper of the Grove, Frothing Berserker and possibly Mogu'shan Warden or Oasis Snapjaw.) Against a Paladin or Shaman, you can almost always get value of it's battlecry, and it's another beefy body to give taunt through Sunfury Protector or Defender of Argus. Also, it's a 5 drop. You might prefer Azure Drake, but there's a lot of ways to do 4 damage (Truesilver Champion, Soulfire, Argent Commander, Eviscerate spell damage totem Lightning Bolt etc.) It's quite a bit harder to do 5 damage.

 Power Overwhelming.is a 1 cost card for 4 damage. Think of it as a way to deal 4 damage whenever you need to, like a less effective Cold Blood. It'll work as a finisher, and you could use it to activate Wild Pyromancer or Haunted Creeper.