musket ball costs?

[Jaware]

Ladies and gentlemen, I have a problem.

I'm trying to build some muskets for a magic and musket type fantasy game.

That is neither here nor there.

I'm trying to find out how in the world to price musket balls.

To my knowledge, bullets cost 20$ times the weight of the "magazine"

(For musket balls which are weighty, I don't imagine them costing some 80 cents or 1 dollar or so each. That's a little stretch since you are usually casting your own balls so you wouldn't be paying for the work or anything.)

Now. High tech has musket balls that are much much mucccch different in price. That seems more..... reasonable. But I can't find a method to their maddness.

I am confused.

Does anyone have any information?