Molds are running around $40 right now. I think I am down to 14 as I just sold some I no longer use.
You are going to need a mold, way to melt lead, lead supply, hooks, weedguard, skirts and paint.
$40 $50 $2/lb $.25 each, $.10 each $25 $6 for 2 oz
Figuring for your first 100 jigs you would have about $165 plus what ever shipping would cost.
After that the cost goes down as volume goes up.