Hey naners, I'd suggest looking at Sunset Park or Bay Ridge; you'll find plenty of options in that range. There will be fewer options in Carroll Gardens and Park Slope, but I have friends who have found (with lots of digging, some luck, and many broker's fees) junior one bedrooms under $1,500.
However, I'd also really urge you to reconsider living with roommates. It's so, so, so much more cost efficient; you'll pay less in rent, utilities, Internet, etc. I don't know if this is part of your thinking, but there is zero stigma about being an adult and living with roommates in NYC.