It’s not a bad idea to wait for the next sale, if you’re not sure what you want/need. That having been said, if you pick up the things mentioned below I think you won’t regret it (as long as you decide to stick with this hobby, that is).
Given that your primary goal is character creation, if you want to take advantage of today’s sales and have money to burn, I’d recommend picking up Michael 5, Victoria 5 (and/or Stephanie 5), and the Genesis Evolutions morphs. There are some larger bundles that contain these items and would give you a better value, such as this:
or some combination of the Michael 5 Pro Suite http://www.daz3d.com/shop/daz-bundles/michael-5-pro-suite and the Victoria 5 Starter or Pro Bundle and/or the Stephanie 5 Starter or Pro Bundle.
Basically, if you’re going to buy just one item, I’d go with the Michael Victoria Combo Bundle; if you’re going to get two, get the M5 Pro Suite and either Victoria 5 or Stephanie 5 (or better yet, one of their starter or pro bundles). The Michael 5 clothing and hair tends to look good on women, too, which is why I emphasize that.
Note that this all assumes that you want to primarily use Genesis…if you prefer older figures like Victoria 4 and Michael 4 (and note that many people do), then you’d have a very different shopping list.
Also worth considering is the Photorealism Bundle: http://www.daz3d.com/shop/photo-realism-bundle (in addition to the above). The Photo Realism bundle was made for Victoria 4 and Michael 4, but the skins and hair can be used with Genesis as well and it’s a great value…
If you’re going to be spending more than about $20 today, you should seriously consider purchasing a monthly Platinum Club membership, as others have recommended. If you’re planning to spend more than $70 or so, adding a PC membership will actually make the entire purchase cheaper. Also keep in mind that if you spend $50 you get Joanie for S5 free: http://www.daz3d.com/shop/stephanie-5-elite-texture-joanie/ (don’t forget to add it to your cart). Joanie requires Stephanie 5, but go ahead and pick her up even if you’re not buying S5 today…in case you wind up getting S5 in the future.
If you decide not to make a purchase today (or even if you do…) definitely pick up this free morph set which you can use to make customized Genesis characters: http://www.sharecg.com/v/58198/gallery/21/DAZ-Studio/DieTryings-182-V4-Morphs-for-Genesis