Residuum?

[Doug Lampert]

Generally speaking, it's a bad idea to make your currency out of something that has a high amount of Use Value.

True. And Residuum is a CRAPPY currency even without that problem!

I spend 25,000 GP making a magic item, then spend more components and reduce the magic item to 5,000 GP worth of Residuum. The only other listed way that I'm familiar with to get Residuum is from rust monsters and (a) it's specifically not supposed to work at full value if you try to farm them and (b) that STILL doesn't give you a profit even if it DID work at full value.

You SPECIFICALLY can't buy Residuum, you buy normal components at 1-1, but not Residuum, no one is stupid enough to sell it for a "reasonable" price.

NO ONE mints currency where it costs over 5x as much to get the raw materials as the currency is worth! (The US penny currently cost more than a penny to make, but not that much more.)

Residuum is what is left when you destroy a magic item, it's VERY useful, but for the cost of MAKING 100 GP worth of residuum I can go out and BUY 100 GP worth of EACH of the four other components, and have plenty of change left over. Residuum is useful because if you HAVE an item you don't need, and are desperate to cast ritual X, you can still do it. You can reasonably carry some Residuum just to be prepared, but it's not the normal way to do rituals.