If you have a Burlington Coat Factory near you they have had some cute stuff for cheap. Also Ross and Old Navy for reasonably priced stuff.
I like pink blush maternity online. I just got my baby shower dress from there. :) so hard to find a dress that flatters a big belly. Love my dress.
Asos.com has super cute maternity dresses for casual to work to party to formal.
Asos.com
loft.com
nordstrom.com
oldnavy.com
I got my maternity clothes from Amazon
I've gotten quite a few at Destination Maternity. They have good sales and clearance sections.
Oh my gosh I got the cutest dresses and shorts at the thrift store! 5 full outfits for 40$