In the long run, it is cheaper to make Chex Mix from scratch. But it depends on how you look at the expense. To buy everything you need to make Chex Mix, it will cost more than a bag of Chex Mix. But you'll get A LOT more Chex Mix for your money if you make it yourself, and you'll have ingredients left over to make more Chex Mix in the future — or to use in other recipes (like Chex Mix Chicken Tenders!). You probably already have some of the ingredients for oven Chex Mix with pita chips, which means you won't need to buy them just to make this!