I've looked at and purchased a very high quality one (staninless steel ribbing not bone, but it laces up) for around 100 bucks at an Anime Convention- Steam Punk has gotten very popular recently, and Victorian style clothing is back in style in a major way.
Orchard Street Corsets in new york city does amazing work and is very very VERY well priced. You get quality craftsmanship, and a pricetag that is easily affordable.