You have to join Craftsman Club to get this price. Even if you have a Sears.com account, it doesnt mean you're in the Craftsman Club. It's free to join.
If you just joined the Craftsman Club and the price in Checkout still shows $79.99, remove it from your cart, sign out of Sears.com, sign back in, re-add it to your cart, and it should show the $44.99 price during Checkout.
Ship it to your nearest Sears (and in same cases, Kmart) for free shipping.