Go to eBay and watch the auctions. I bought mine in the summer for $610, but they seem to be going for a minimum of $1400 right now. The price seems to depend a bit on the color, where the top is located, and the seller's willingness to ship.
Here's a couple of auctions that recently ended.
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ih=018&sspagename=STRK%3AMEWA%3AIT&viewitem=&item=280046012445&rd=1,1
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ih=018&sspagename=STRK%3AMEWA%3AIT&viewitem=&item=280044734583&rd=1,1