15 rockets to destroy a Armored Wall. That's 21,000 sulfur in raw materials.
8 C4 charges to break a Armored Wall — roughly 17,600 sulfur plus metal fragments and tech trash.
46 satchels to destroy a Armored Wall in Rust. Satchels have the best damage-per-sulfur ratio on soft sides.
The cheapest explosive option for a Armored Wall is 223× Beancan Grenade at roughly 13,380 sulfur.