If you pitch in $450 you will get a signed map of Westeros, $600 gets you a signed and dedicated GOT cookbook, and $1,200 will reward you with a handwritten thank you note from George.
Now, onto the good stuff. Unfortunately, people already snatched up the episode one script (signed by the cast and crew) for $4,500, the pair of tickets to the season five premiere for $7,500, and George's worn hat for $7,500 (which seems like an odd thing to spend that much money on, but no judging).
Perhaps the coolest prize that was on offer, for $20,000 two lucky fans scored the chance to appear in the next novel as a character with the societal station of their choice (who will, of course, be killed off some magnificent way. Sadly most of the campaign sold out faster than a 90s 'N Sync concert, but you can still snatch the $15,000 breakfast with George, where you may be able to convince him to sneak you in the book too (*Just kidding, that just sold as well).