I went with the MotoBacon FB4 Comp for $700 back in October and have been putting it to the test ever since. I upgraded the drivetrain with some parts I had sitting around, ditched the Vee Missions for Nates, and added a bashguard which has turned it into a solid bike for under $1k. My guess is that you will want to make all of those changes and maybe more (except the drivetrain?) to the Nashbar bike which will put you around $1200.

My biggest issue with the Moto is the wheels. The rims are Weinmann double walled rims which have been a huge PIA to get set up tubeless, especially when compared to the Surly Darryls. I just had my 2nd tubeless blowout on the front wheel while riding SBP on Sunday which was less than ideal. I would assume that the rims on the Nashbar bike are also some variation of Weinmanns, so beware if you want to set it up tubeless...if you plan on running tubes (pinch flats and thorns suck) then they are not an issue.

They are great deal to get you started fat biking for cheap, but they are definitely a lower quality bike than the Surly, Salsa, etc. Anyways...that's my 2 cents on the budget fatties. Feel free to PM me if you have more questions.