Cathy makes pj's and has robes on her site:
Washable and reusable dog and puppy pee pads, belly bands, and diapers by T. Bumpkins & Co.
I have these coats for my dogs that I actually use as robes when they get out of the bath sometimes:
http://www.phantomphleece.com/coats.html
I have also gotten cute pj's from:
FuFu Fashions custom dog clothes and apparel
Also look around in the for sale section here- many times you can find good deals on used clothes from other members.