I had watched a ton of videos on you tube prior to ever processing my first birds. One small organic farm used them. It does add to the overall cost but in my opinion well worth it. My vacuum seller broke and this was a cheaper way to go.
After searching around for the bags I finally found them by chance on the Whizbang site. I bought a starter kit . I think it was 25 bags, tiny zip ties and freezer labels for 19.95. Of course the more you buy the cheaper the bags get.
They are super easy to use. I will find the video link.