kkpro -- many of us buy in bulk. A little extra work but dirt cheap!
Sam's Club sells ActII popcorn, 50lbs for $17. I'm still going through mine many years later. Then you can pick up some coconut (or other) oil and Flavacol seasoning. In the end, for the price of another case of Megapop, you have a multi-year supply!
Also, the packs for 4oz kettles are almost the same price as 6oz and 8oz, because of the initial packaging cost rather than supplies. So your cost/benefit with a smaller kettle might be even better buying bulk!