The real cost of something -- anything -- is how much time and resources it costs you, or your organization, to build or execute that same thing. Let us ignore, for the sake of this discussion, that cost does not correlate to value; there are obviously lots of vectors to factor in when evaluating something, and most of them have little or nothing to do with immediate costs. However, one truth remains: doing something yourself is the only way to properly evaluate the returns of investing into the acquisition of a good or a service versus using your own means to derive the same.
Let's imagine you need to bring a cake to a birthday party. You could either (1) bake a cake from scratch, or you could (2) drive to the nearest grocery store and buy a cake for $20.
Let's try option 1: doing it yourself. You'll need all the ingredients. You'll need time. You'll need skills, both to mix and bake the batter, and to decorate the cooked result in a satisfactory way. You'll be taking risks -- you could end up with a complete failure. Or you could bring bring home the best cake the guests will have enjoyed in a long time.
Now let's try option 2: you hop in your car, pick up a nice-looking cake at the bakery spot, and store it in your fridge until it's time to go to the party. Now you have all that time on your hands, spent relatively little on the task, and you have a cake ready to go. Of course, the treat will taste bland and overly sweet, but that's how the industrial bakeries make their money out of saving you time.
Unless you've never tried your hands at baking a cake -- and do so until you get satisfactory results -- you will probably never know 1) what it takes to bake a cake, and 2) how bad store-bought cakes really taste in comparison.
The same can be said about making videos: unless you, or your marketing team, tried to make one yourself, you won't really know what it takes to go from a vague concept to a complete, enjoyable video. A recent, rather long, and to be honest somewhat confusing (you have been warned) post entitled: DIY Video Editing: What to Know to Get the Most Out of Your Time will give you a good example of all the elements and processes that go in making your own video. I cannot but encourage you to try it out. Don't take the author's words for anything, until you've done it yourself. Your results may vary, and in many ways, surprise you.