I LOVE kale chips, especially as I work on eating more whole foods (Whole 30 is an inspiration). But at $5.99 for a 2.2 ounce bag, I don't like the cost.
I got a bunch of fresh kale for $1.50 at our local cheap Russian grocery store. Removed the stems, washed the leaves, and spun the kale in a salad spinner. Then you massage in oil (I used olive, though I know people who use coconut and other oils) until the leaves wilt a big and turn a darker green. Then I added lime juice and salt, mixed, and spread out on a cookie sheet.
Bake at 160-200 for 90 minutes, flipping and redistributing until it's all crunchy.
About 2 bags worth of the retail stuff, saving at least 85% the cost. To be fair, I didn't use organic kale, but this summer I will plant a TON of it -- red kale in particular is super easy to grow (an investment of a few bucks in plants or just seeds could give me a few hundred dollars in harvest), and if I can figure out how to dry it and keep it for longer periods of time I could have a huge kale chip stash!
Some people add grated parmesan, soy sauce, or make cocoa kale chips -- I plan to experiment. My kids love them.