This reduces the build cost for all the contraptions in the workbench. There are no scrap bonuses for this one, so I highly recommend using all of my other Less Resource mods to make massive builds a breeze:

Less Resources for Settlement Builds Base Game

Less Resources Automatron

Less Resources Wasteland Workshop

Less Resources Far Harbor

Less Resources Vault-Tec

Bonus Alert: Fireworks are made in batches of 10 using this mod! (Underwhelming Cheers Heard Here)

Homemaker Mod Users: I wanted to make you aware that NovaCoru has updated to patch 1.35 for Far Harbor. This also works (at least for me) with Contraptions. I only mention this because it is a relatively recent fix and will significantly expand the settlement build menu.