I have had a Foodsaver for many years. The least expensive bags are the ones you make yourself from rolls. However, if you are making meal size pouches, it will take a lot of bags and using the preformed bags is a lot easier. I have use Foodsaver bags, Wevac bags from Amazon, and Old Mill bags that I get from my local Menard's store.
All of the options seem to work well if I follow the procedures listed below.
The primary cause of seal failure is getting water or oil on the part of the bag to be sealed. If you will fold the tops of the bags down about 1" before placing food into the bag, you will usually avoid that problem. That keeps the top dry.
With super-juicy foods like pulled pork, I occasionally find it necessary to place a small piece of paper towel into the bag along with the meat to absorb excess juices. Otherwise, the vacuum pump can pull juices right out the top of the bag and affect the seal.
