Get a few items you can mix and match to maximize your collection! Make sure you have at least one pair of maternity jeans, with which you can ware maternity tops, maternity tunics or if you plan on nursing, maternity tops that are nursing tops as well (this is a great way to save later on when your baby arrives. You will already have the attire for discrete nursing).
Maternity tights in any solid color can be used with any maternity top or maternity dress and will spice up your look as well as help support your growing belly. When shopping for maternity pants, make sure you can grow into them! Remember - your belly will do most of its growing in the third trimester.
A belly band will go a long way allowing you to use other top in your closet you may not ware otherwise.