Best Buy offers the SPOT 2 Satellite GPS Messenger, model no. SPOT-2, for $44.99 with free shipping. That's the lowest total price we could find by $30. Features include an OK feature to alert friends and family of your location and an Alert 911 feature to notify emergency responders. It requires three AAA batteries, included.
Of note, a service contract from SPOT may be required in order to use this item to its fullest capability; click here for more information.