Amazon has got this 2-pack of 40 oz. jars of Jif Creamy Peanut Butter (80 oz. total) for $9.96. Just to put this into some perspective, since this is not a common size for peanut butter, it's about 12.5 cents per ounce, which is like getting a 16 oz. jar for $2.00. Because of the low pricing, there is a limit of 4 per account.
This is an Amazon Add-On item, which means that it ships for free with a $25 minimum order if you are an Amazon Prime member (and its price of $9.96 counts towards that $25), or it ships for free with a $49 minimum order if you're not a Prime member. You can buy multiples of this item to help get you to your $25 or $49 minimum for free shipping. (Other Amazon Add-On item deals can be found here.)