i've been riding motorcycles in the atlanta metro area for the last 7 years. My advice is like this:
1. if you want a more economical commuter option, get a used Toyota Tercel. The insurance will be cheaper to add a vehicle vs. a new policy for a bike, the mileage will be similar, and it will be much, much, much safer.
2. if you really want a two-wheel vehicle for commuting, a scooter will give you the best mileage. I don't recommend it if your commute is farther than 20 mins.
3. if you want to get a motorcycle because you want to "get into riding", AND you can ride to work, well right on. For v-twin cruisers, a Yamaha V-Star 650 is probably the cheapest of the "looks like a Harley"'s. Or a Yamaha Virago. These are both great bikes you can find for about $1500-2500 bux. For racebike style, an older ninja 600 is a good bike cheap. And of course, you can get any 70's honda or kawi like the CB360 pictured above for $500-1500.
the insurance in GA for my 4runner, with liability, comp, and uninsured motorist is about $450 annual. for my V-Star 1100 with the fullest practical coverage, its the same. I recommend Dairyland Insurance.
4. That all said, I've totalled my first two V-Star 650s thanx to poor GA drivers running me off the road or hitting me. GA commuters are accustomed to yappin on the cell phone and paying attention to anything but the road. IT's DANGEROUS TO COMMUTE HERE ON A BIKE. It's not even a matter of keeping your eyes open. Sure, you'll have your eyes right on that vehicle that suddenly goes where they don't have right of way. Unless you have the skills to jump a moving vehicle, they'll get you and you're just a spectator in your own wreck.
5. DEFINITELY TAKE THE MSF SAFETY COURSE. Even if it teaches you one good thing, its worth it.
6. When I ride, I have one thing I try to remember: Don't misoperate the controls; and everyone is trying to KILL ME.
if you do get a bike, lemme know, i'll ride with ya anytime! but i really recommend a Tercel for cost-efficient commuting purposes. People are tired and distracted in the morning, and distracted and hurried on the way home. They will run you down then act like its your fault for being in their way.
Bikes really should be a leisure vehicle AWAY from traffic, not a target within it.
good luck in your decision