I know I saw the one for K-Mart earlier, but if you take five minutes to register for Rewards Zone, then a quick click to also join the Gamers Club, you can get a coupon for an additional $10.00 off of Blur.
$20 Blur Promotional Coupon(coupon install is totally safe, nerds honor)
$10 Gamers Club Coupon
The $10 Gamers Club coupon, the Blur $20 promotional coupon, and Best Buy having Blur on sale for $39.99 all comes out to $10 before your taxes. For me(AZ) it came to $12.93.
WARNING: You may run into a jerk cashier that gives you the whole "can't combine coupon offers" jerk around. You know how that goes. So this deal is kind of a 50/50 chance of happening. Me and 4 of my friends had no problems. Best of luck to the rest of you. Game is well worth the price, even if you don't get the additional $10 off. Enjoy "adult Mario Kart"!