http://www.animetraders.com/showproduct.php?product=530&cat=500 - A nice white chemise bought from ebay earlier in the summer, so it's barely been worn (though wrinkly from storage). $12US
I have several other items over at Anime Traders including costumes, shoes and games! Please take a look!
x-posted in a lot communites. Sorry if it shows up multiple times for you!