When weighing metal to figure its cost, remember that besides the
spot price of whatever there’s also the milling fee. Personally, I
mark the total cost of each mill good on its packaging, divided by
ozt or dwt (as relevant) and also as linear measurement for wire etc.
I include the shipping- pro-rated- in this.
Keystone, or triple keystone, works great if one is basically
assembling prefabricated components. If one is doing much fabrication
oneself, one needs to add one’s time and effort (and studio costs) to
the price. And then one needs to look at what the market might bear,
and adjust- sometimes up, sometimes down (though if it’s too far
down, that means that one should not make that design).
I usually use keystone, plus labor etc., for pricing. It’s one of
the hardest parts of making jewelry for sale, that’s for sure! And
for some things, I’m not making that, though I’m trying to either
make those items more efficiently or phase them out.