Short answer
The cheapest sulfur method is often explosive ammo or satchels, but the best method depends on speed, safety, splash value, and counters. Use cheapest as the starting point, not the final decision.
| Target | Lowest estimate | Tradeoff |
|---|---|---|
| Sheet Metal Door | Explosive ammo: 1,575 sulfur | Slow and exposes shooter. |
| Garage Door | Explosive ammo: about 3,750 sulfur | Lower sulfur but high time risk. |
| Stone Wall | C4: 4,400 sulfur | Fast but no splash. |
| Sheet Metal Wall | C4: 8,800 sulfur | Good direct damage but expensive inventory. |
| Armored Wall | C4: 17,600 sulfur | Only worth it if the wall path is truly best. |