I second the idea of just making it yourself. If you really love beef jerky, dehydrators are a good investment. Just know, once you use a dehydrator for jerky, you'll probably never be able to use it for anything else (the smell and seasoning will stick). I dare you to try making fruit rollups after a batch of jerky.
That said, all I do anymore is make my own. I use an electric meat cutter and slice up 3 pounds of brisket (about $15, as McNutsnack accurately stated) into strips. You can trim the fat off, but I'd suggest leaving some on for flavor. You also have to factor in the cost of seasoning. Among some of the ingredients I use to marinade are worcestershire sauce, a little liquid smoke, Frank's Red Hot, black pepper, onion salt, garlic salt, soy sauce and black bean sauce.
Usually costs me about $20 worth of meat and ingredients when I get the jerky itch, and that does make about 1 pound of jerky. But it's comparable to grocery stores around here.
Jack Link's doesn't even give you 4 ounces for $4.50 anymore. You really are better off making your own. PM me if you have any questions.
Oh, and I don't think anyone else said it yet, but you can use your oven, too. It won't smell up your house much more than a dehydrator, but it will warm it up. Probably not a great method for summer.