Below are two links from singletracks.com. The first is a pretty comprehensive list of budget fatbike offerings and the second is a list of mid-range fatbike offerings. It is pretty amazing to see the number of companies now offering fatbikes, along with the components now available.

http://www.singletracks.com/blog/mtb-gear/fat-bike-buyers-guide-budget-models/

http://www.singletracks.com/blog/mtb-gear/fat-bike-buyers-guide-mid-range-models/