To make pecan pie, you'll need to buy, aside from the basic ingredients, corn syrup, which costs a modest $2 or so, along with the titular pecans, which is where things get expensive. A 16-ounce bag of pecans can cost almost $11, but if you compare that to a $6 ready-made pecan pie in Walmart or an $8 one at Target, the pre-made pies look attractive and light on the wallet.