Not enough, apparently. Am still in the process of trying to work that out.

Sigh. Thankfully my levels aren't yet too far below the normal range.
Too much copper is a very bad thing. But it also has to compete with zinc for absorption, and vitamin C is apparently also antagonistic to it in high doses. And low copper is also quite bad.
I'm not sure how common it is to have problems, though. It's supposed to be a very rare thing. As an interesting side note that probably doesn't mean anything, though, apparently issues with the methylation cycle are also one of the hypothesized causes of some copper deficiencies. For me it may also have something to do with not processing zinc properly. I already know that something's wrong there for me, since I get vertigo from even very reasonable amounts.