I'd take out Mental Agony . It's really slow.

4x Duress is a must. Sometimes, all you need to destroy a perfectly good hand is one Duress .

I'd drop Hellion Crucible . It's simply not competitive enough for even a casual FNM. It's 9 mana and -1 land to give you a 4/4 haste.

You need more win-conditions to win with once your opponent is top-decking crap. Desecration Demon is okay, but it can simply be tapped down each turn until your opponent comes up with something like Oblivion Ring to permanently remove it.

Honestly, I'd use Auger Spree over Ultimate Price . For one more mana, you're killing 90% of the creatures you'll be running into in Standard, including Multicolored creatures. Also, Auger Spree kills creatures that could otherwise regenerate.