Shoes....*drool*

:lol:
I'd go with an open toe, closed heel shoe with a medium heel (2.5" seems to work very well) and enough straps to not wiggle on your foot at all.
I'd also buy it in skintone satin. Although leather tends to keep decent-looking longer, satin shoes don't stretch as quickly, so they're wearable longer. Dance Naturals are my brand of choice, both for comfort and durability. I recommend latin (open toe) shoes because it's nearly impossible to really point in court shoes, while dancing smooth in sandals is passably possible. If your heel isn't too high, even heel turns are doable in sandals, although not nearly as nicely as in court. If you're only buying one pair, go with sandals.
If this is your first time buying, try them on first. I used to go to competitions and try on shoes from various vendors, and then buy the ones I liked online (sneaky, I know, but it saved me $30/pair or so, and I am a poor student too).
I would not buy dance sneakers as the only pair. For one thing, the sole over the ball of the foot is inflexible, so you can't work your feet the way you should. I also dislike not being able to feel the floor, but that's just me. :?
For your arches, there is a great exercise that will strengthen them in a matter of weeks. Stand on one foot, keeping the other completely off the floor. Slowly rise to your tiptoes (on a slow 8 count), then slowly lower back. Do not rest your heel on the floor between raises. Do as many as you can, then switch. You can keep a couple of fingers on a wall for balance if you need to. I did those 5 times a week when I was getting arch cramps from too-high heels, and after two weeks the cramps stopped. I firmly believe everyone who wears heels should do this, it does wonders for your feet.
Good luck! Shoe-shopping is fun, but stressful. But fun. :lol: :roll:
Couldn't you ask your parents to buy them online with their card and then pay them back with cash? That way they won't have to give you the # and you can still get your shoes. It's just so much cheaper.