Digital scales are a critical piece of kitchen equipment, especially when doing any sort of baking, and I'm constantly baffled as to why so few recipe writers suggest them. From a writers standpoint, it's way easier to develop a recipe by weight. Simply weigh all your ingredients, cook by intuition, then weigh what is leftover. The difference is in the dish, thus, your recipe. Though it looks like science, it's actually just the easiest way to express cooking by feel. This is how I do it—which is why you should also feel free to adjust some of the weights to suit your palate (except for baking of course).
But digital scales are also extremely beneficial for the cook. The smart folks over at chefsteps.com did a fantastic job demonstrating, in two short videos, why it's to your benefit to go spend $30 on a scale.
Again, a good scale is only $30. That's 1:10th the cost of the stand mixer most recipes ask you to buy. So go get one already. And if you end up not using it for cooking, at least you're that much closer to having the meth lab of your dreams.