How much you are planning to buy is exactly how much you will be spending. Keep in mind that some of the retail stores are more on the expensive side, despite Atlanta's overall relatively low cost of living.
You may take this tour using the MARTA trains and buses, however, if you plan to buy in bulk taking a car would be more conveniant.
Begin this tour in Buckhead. By train, take the MARTA North-South Line to Buckhead Station (N7), or take the Northeast Line to Lenox Station (NE7). By car, take GA 400 and exit Peachtree Street and proceed eastbound. About one block east of the Buckhead Station (which is above GA 400), is the Lenox Square Mall. This is one of the largest and most popular malls in Atlanta, and local celebraties have been spotted there. Be careful to park in this Mall, there is a parking enforcement firm that will fine you for $50 if you go in the nearby area. I suggest to avoid this place and to go about one block further east of Lenox Square Mall where there is Phipps Plaza, another upscale mall with expensive designer brand stores. Also, opening in Fall 2009 is the Streets of Buckhead, an area designed to rival Rodeo Drive in Beverly Hills. The Streets of Buckhead is approximately 1 mile west of Buckhead Station and GA 400, so you may want to drive or take the MARTA #23 bus. Another option is 3344 Peachtree, a mixed-use development in a 50 story skyscraper right next to Buckhead Station.
Next stop is Atlantic Station . By train take either the North-South Line or the Northeast Line to the Arts Center Station (N5). A free shuttle is provided to Atlantic Station from Arts Center approximately every 5-15 minutes. By car, take GA 400 to I-85 South, then exit 17th Street and turn right. Atlantic Station offers plenty of apparel, accessories, and department stores.
Head back to Midtown across I-75/85 via 17th Street (or catch the shuttle back to Arts Center Station), and opening Fall 2008 is the completed Midtown Mile , a mile stretch of Peachtree Street between 15th Street and North Avenue with numerous street level retail and boutique stores.
By train take the North-South Line from North Avenue Station (N3) to Five Points Station. If you're driving, you may want to skip this part of the tour, as parking in Downtown|Downtown may be a hassle. Adjacent to Five Points Station is the historic Underground Atlanta, which offers a variety of shopping options.