This week's deal for Xbox Live Gold Members is the Zombie Island of Dr. Ned content for Borderlands.
Your price? 400 
. Which is 50% off the normal $10 asking price.
The pack contains a ton of new enemies, a new locale, and dozens of missions to play through with up to four people in co-op. Want to know more? Read our impressions. But for $5 this seems like a steal.
Source: Marketplace.xbox.com
