Cheaper TNT

In the current vanilla minecraft experience, creeper farms are a requirement if you want to use tnt for any real terraforming or mining. In my current no-farms playthrough I have been testing how much gunpowder I get after a full night of fighting on the surface. Even with looting three I am only getting ~3-4 blocks of tnt per night. I'd like to increase this amount so that I can use tnt for more terraforming during the day, and this recipe feels like a good balance.