The site you're looking at is for late Victorian costumes. The Titanic sank during the Edwardian period, so perhaps this site will suit you better http://www.bustledress.com/cgi-bin/z.pl//room325.html
My guess is that they are probably not worth much more than what you paid for them. Collectibles tend to be rare or have a limited production run and Disney products are usually made by the millions. You can get a sense of how much they might be worth by searching for Ebay auctions of similar items.
It could be triggered either by a pressure switch that your guests step on, or by a motion sensor spliced into the electrical line. I've linked how-tos for both.
If its a commercial site like a retailer, you can complain to the Better Business Bureau if a transaction has gone wrong.
If an informational or chat site, there really is no governing body. You can send a complaint to whatever company is hosting the site, or if there are advertisers you can...