I bought 3m of thin cotton material to make Um of Umbridge's dress (tim Burton's Alice in WOnderland), but have decided against making it. There is a little under 3m of the fabric left (after I cut the bodice pieces): still enough for a small or medium sized person to make the dress. The material is thin and soft, with little 'embroidered' knots in it, which add some texture.
Price: 10 Euro
Post: Depends where you live.