You absolutely don't need a tutu for class work, they are a costume item.
You will need: Leotard (Black is your best bet), Ballet tights (in ballet pink), a ballet skirt or ballet shorts (if allowed by your studio), and a soft slipper (I'd suggest leather unless your studio states otherwise. They strengthen your feet).
You can get overnight shipping from Discount Dance Supply (google them). Their prices are very very reasonable (about $10-15 less than in stores) and they offer only premium dance brands.
I'm not familiar with the shops in Boston, but try your phonebook.
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