I have never seen them at either Trade Fair on 30th Ave. - I would second tigerwoman's suggestion of Patel Brothers. They usually carry them at Kalustyan's and Little India in Manhattan, but of course that's not Astoria either.
Ditto. In 3 years living in Astoria (and shopping pretty regularly at Trade Fair, Bravo and various bodegas -- even the Bangladeshi one at 31st & Bway), I've never found curry leaves. But you can definitely get them in small or big bags at Patel Brothers in Jackson Heights.