AlsSports.com has Thule SnowPack Extender listed for $229.95 while other sites list it for $299.95. With PRAY4SNOW coupon, the total comes out to $183.96 ($45.99 off their listing price). No taxes for CA and free shipping.
I just placed an order myself - will follow up once it arrives.
Order arrived on January 17 - the box was damaged but otherwise a complete set as I hoped for.