Price the show, not the shell. A line of five boomers on a roof, violet in the middle, comes to 300 sulfur once you unfold the gun powder, plus the fuel and fragments. Type five into the calculator before anyone goes farming, and split the powder crafts between teammates, since a Level 1 bench is all they need.
Fill the gaps cheaply. A roman candle between two boomers keeps the sky busy with no powder at all, and the order and spacing are laid out on the item page. Close on a White Boomer if you like a quiet ending.
There is nothing to research. Whoever owns the item crafts the shells at the end, while the others bring the powder.
