Before you farm, look at where the sulfur goes. The rocket's own gunpowder is the small part; the bulk sits in the explosives, which need their own blueprint and a Level 3 workbench. So the research that unlocks rockets is the explosives one. A rocket blueprint alone only turns looted explosives into rockets.
The calculator counts each metal pipe as is, because most groups never craft them. They come from road barrels and crates, and back out of the guns you recycle, a pump shotgun or a revolver among them. Unfold them and every rocket also asks for high quality metal and scrap at the Level 3 bench.
Craft the gunpowder first: 65 crafts of it, the slowest step at the bench.
Turn it into explosives the night before the raid.
Keep explosives, powder and pipes in one box and craft the rockets on raid day.
If the target is players or a minicopter rather than a wall, a high velocity rocket costs a fraction of the sulfur and needs no explosives.
Questions
Rocket ×10: how many resources?
Sulfur ×14,000, Charcoal ×19,500, Metal Fragments ×1,000, Cloth ×75, Animal Fat ×225, Metal Pipe ×20.
