The normal subsidized price is $529.99, but potential buyers can knock up to $100 off that price if they simply order the G-Slate by phone. Apparently there's a little process and code that has to be given, and TmoNews has the details.
Sure, ordering online is the easiest option, or maybe you'd rather go into the the store and have the Honeycomb-based device in your hands the same day. However, it might be worth it to just pick up the phone and make that call if you really want this 8.9-inch HD tablet. The deadline is Wednesday, April 27th.