Amazon has the 4-Pack 40oz Jif Creamy Peanut Butter for $23 - 25% off (check “Save an extra” box, eligible on first S&S order for this product) = $18 with free shipping on $25+ or with Prime (extra 5% off for 5+ S&S orders). Roughly $4.54 per jar vs. $6.78 at Walmart. Around 11 cents per ounce. 

Need a No Sugar Added option? 8-Pack JIF Creamy Peanut Butter (33.5oz) for $31 after coupon, S&S. (11.5 cents per ounce)