I currently commute about a mile to work each day in upstate New York. For the past year, my ride has been a 2012 Specialized Tricross with a 3x8 setup, which has treated me very well in this snowy and hilly area. However, my ideal commuter would be a cromoly frame with only a rear derailleur, perhaps 1x8 or 1x9 with a 11-32 casssette and trigger shifters.

I just came across a brand new single speed State Bicycle Co. Brigadier frame (link to specs) on CL for $200, which is half what the bike would normally cost. It's in pristine condition, so I'm thinking about using this as the base for a new commuter.

My question is: What kind of issues might I run into with this conversion? What might this cost (I'm looking to watch my money, but I don't want to skimp on quality)? Any recommendations for reasonably-priced and reliable parts?