Don't worry about poles, just walk into you local goodwill or thrift shop and find some one that fit you for cheap.
As for boots, the best option is to go to a well known shop and get you foot properly fitted to a boot. Not all ski boots fit the same, some are wider or narrower, etc. It really does make a difference, too. However, if your foot is still growing, the boots you choose aren't quite as important, just make sure they fit your foot reasonably well because you will need to wear them for the next year or two. If/when your foot is done growing, look into getting some properly fitted boots from a shop. This will probably put your total above $700, but it'll be worth it in the long run.
Bindings are another thing that aren't too important first year, depending on your weight you could get a good deal on bindings like the Marker 12.0 Free, or the Salomon Z series/STH 12.