An alternative to gemming out your build time.
For 1 gem per hour of build time, you can add scaffolding to any building already in construction, given that you have a free builder. Scaffolding adds an additional builder to the work in progress and decreases the build time by 30%.
The downside is obvious - the user loses another worker. In my opinion this might be cost effective for Supercell as more players would use this option over the high cost of finishing something.
