Edited for Confirmed Information:
It is not. It is going to be 39.99. I work at gamestop and I have the ad. I will post the new ad soon.
GS will have Gran Turismo 6 for $39.99 from Dec. 26th to Dec. 29th. My local GS provided information stating the price was for $29.99 (with the standard wink and a shush), but I appreciate the confirmed information all the same
Thanks to Dante84 for the confirmation!