i am being alice for halloween too, and actually its not that bad
all you really need is a pair of white leggings-target, 5$
a pair of black flats-target, 14$ or you probably already have them
a black hair ribbon-silky or grograin-fabric store, around the house
the only issue is the dress...i actually have an alice dress which you can buy from any evangelines-high quality costumes-or costume shop...just make sure it is the style you want, becuase some are slutty, some are long, some are cheaply made. if you don't want to buy, or can't find the right thing, fashion on yourself...not too hard either. just find a short blue dress (neckline doesn't really matter) or if you don't have one, a blue skirt and matching blue top with at least cap sleeves. this is tricky, the dress is the better bet becuase you have to match the color right so it doesn't look awkward. the last thing is the apron. this should be relatively easy to make, and if you cant construct it off the top of your head (all you need is white cotton, maybe a length of lace, and a white ribbon for a waist tie) im sure you can get a pattern at a fabric store (and not make it as long) or find instructions online.
halloween, and i've been planning the perfect costume for weeks!