I go thro the same thing, I love to buy Pita clothes but I am not paying more for her clothes than I do for mine. I get some of them from ebay but there are some reasonably priced places out there. This lady, Reva, makes really good quality dresses and panties:
http://queenbk9.smugmug.com
You can also order from barkindogclothes.com for custom t-shirts, also
www.lovelonglong.com has cheap stuff!
Have fun!