Oh I set my prices just so I can keep buying things to craft with, I'd never get any sleep if I couldn't thinker, so I don't charge more unless you need a third batch, and even then I just charge what it costs me at that point, after all there is no need to be unneighborly and honestly in a few hundred years I'm sure people will want something else instead of round bits of metal, so why build up to big of a pool?
How many Weaknesses would you like? I'm sure we can get another crafter to make a few quivers if you need a very large amount.
10 Weakness coated arrows would be 26 silver, or it's equivalent in gold, I guess I could take copper too, but you'd have to provide a hefty bag to carry it around in.