Okay, $4 for a frozen crust is crazy! I've seen them for like $2.50 at my store. Still, your homemade dough is way cheaper and better, so you're totally winning. For sauce, I just use the cheapest can of crushed tomatoes I can find. A little garlic powder, dried oregano, salt, and a pinch of sugar cooks up really nice in about 20 minutes.
Actually you want to skip the garlic powder and use real minced garlic if you can. Cook it in a little oil for a minute before adding the tomatoes. Powder burns fast and gets bitter, fresh gives a way better flavor base.