I would just do a 4 ounce batch & see how many you get out of that & multiply it by 32. If selling baits i personally wouldn't figure remelting the sprue into it because that will be pure profit. Say you get 5 stick baits for every 4 oz. batch X 32 would be 160 baits divided into the cost of a gallon of plastic at 50.00 which is pretty high because it can be bought cheaper. That would be a little over 31 cents a piece plus cost of glitter softener etc. would get you around 40 cents per bait. This is just a rough estimate, but anyway you get the idea. Then the remelted sprue can be used to reduce your cost for those 160 baits you just made by seeing how many you can make out of it which in turn means more profit. You're probably going to get at a minimium another 40 out of the sprue which is atleast 200 baits per gallon & that drops the cost to 25 cents a piece leaving you at $6..25 per 25 pack.