I absolutely LOVE this woman's work:
http://www.wildehunt.com/
Her work is all completely custom, all leather, and start at $400 for an underbust and $600 for an overbust corset, which are actually very good prices for custom work.
If you're on facebook, you can also get a regular corset fix from her at
https://www.facebook.com/wilde.hunt.corsetry.