The short and to the point reasons for this can be explained by taking a simple gander at the instructions:

Prepare a "stuffing" that is not very liquidy (I used chicken, mushrooms, olives and feta)

Make pasta sheets

Brush sheets with beaten eggs

Scoop out 1 teaspoon of stuffing and place a few spaces apart on the 1st pasta sheet

Place a second pasta sheet on top

Use a pizza wheel to cut into squares

Seal each ravioli by pressing the sides down

Place finish ravioli on a baking sheet and let dry for about 30 minutes

Freeze if you can resist cooking them right away!

The cost of the pasta alone was 2 cups of semolina (about 50¢, 2 cups of white flour (about 25¢, a small amount of olive oil, and warm water. For 4 servings. (here is an eggless recipe for you)

For filling I used only leftovers, but let's assume that I had no leftovers. About 1/2 lb of chopped cooked chicken thighs (2.50$), about 4 ounces of mushrooms, chopped (50¢, maybe 5 or 6 olives, and about 4 ounces of feta cheese (1.50$) and the egg for the egg wash (25¢

So much total for 4 servings (and this was quite a large serving) was about 5$ and these were infinitely better than the pre-packaged you find at your supermarket. The work involved was quite easy and weirdly relaxing.