With legalized sports gambling in the U.S. about to become a reality in many states, regional casino operator Boyd Gaming (NYSE: BYD) is gearing up to go on a spending spree. It just increased a debt offering from $500 million to $700 million and says a portion of the proceeds will be used for acquisitions.Boyd hasn't exactly been reticent when it comes to making acquisitions, and today owns or operates 24 gaming properties in seven states.