I hope you bought it real cheap. Anyway, during the plants life in that container it has been watered way too much and fertilized way way too often. There isn't anything you can do for most of the existing foliage but the plant is salvageable. I would then repot into a larger container with a mixture of good potting soil and garden soil (not Scotts or Miracle Grow). I would remove all of those lower nasty looking leaves. I would let it accustom to its new home for a week and then I would fertilize it at half the rate with a good liquid fertilizer, again not Scotts or Miracle Grow. Put it in the sun out of the wind and try to keep it above about 60F. On a positive note, I do not see any fungal problems now. The reason to repot is that the plant is under stress and any stress will make it easier for the plant to acquire problems