right, yes. So you make a cursed item to hurt someone else. That means the someone else will be wielding it, not you, is the idea.
Look at the example weapons with curses. It isn’t something you want to wear in most cases. Making an item that gives persistent damage will eventually kill someone, or keep them at 0HP at the very least.
COLLAR OF CHOKING
Wealth Level: 1
This plain steel collar will choke the life out of anyone who wears it.
Properties: Cursed (Persistent Damage 2)
This would be nearly a free item that could completely take someone out if it decreased the WL.
That versus something like this item:
Which gives fatigue, but doesn’t constantly inflict it fatigue like cursed would, and thus lowers the WL as a drawback to using the item.
How much the drawback reduces is a hard thing to determine based on setting and what the item gives, thus there is not a mechanical means of determining the reduction in cost, rather you do it case-by-case with the item.