Loose or carded? The asking price depends on how it is, and how much the seller thinks it's worth. One from the Stone Set might go for less than the single carded version.
Right now, while there are some nice low starting bids on eBay, (you may have luck), your best shot: http://www.whona.com/mm5/merchant.mvc?Screen=PROD&Store_Code=W&Product_Code=5ROMAUT&Category_Code=DWTE