Hmmm...have any of you tried Motherhood? (In store, or online) They have regular and plus sizes, and they have some very nice sales. They often will have in store specials, like two maternity tanks for $20 and things like that.
They also sell nursing clothes and bras.
Have you tried eBay? There are lots of women selling gently used maternity clothing-lots of nice things on there, too.
For nursing clothes, I highly recommend Motherwear. More expensive, yes, but the QUALITY is wonderful. No cheap sewing, cheap fabrics, etc. NICE stuff. Things that will last through multiple babies.
Buying regular clothes in a size or two larger NEVER worked for me. I had 9+ and 10+ pound babies, and looked like I was carrying twins. I would have had to buy regular clothes 3-4 sizes larger to fit over my huge belly, and then the shoulders/arms and other parts of the top would have been way too big. I would have looked like a big bedsheet.

Maternity clothes worked much, much better.
One of my FAVORITE outfits with my youngest baby (almost 2 now) was a pair of denim overalls that I bought off of eBay, and they were a more modern DARK colored rinse, and they were CAPRI length. VERY cute!
I bought 2 t-shirts from Motherhood maternity (prob $10-$15 each) one in black, and one in chocolate brown. I wore them with the denim capri-alls, and either black, or brown flip-flops, depending on which color tee I had on. I got so many compliments on how comfortable, but stylish the outfit was.