Where do things get their strange properties? From value.

It may be because they were given to us as a gift, or because they are not common, or even because we can't live without them.

Without value, they will be nothing but mere matter, mere objects we are in, on, under, around.

Too much value causes problems. One thing with too much value put into it becomes more important than another that's supposed to hold more value. Order is disrupted as people tend to become more violent as they compete for that thing. Once it is acquired, it will revert to its true value, causing depression.

Too little value causes problems as well. The lack of it causes things to fade away and disappear. When people need them the most, they most probably won't be there anymore.

Item magic is a delicate matter.