There was some talk a month or two back about the copper/gold...

There was some talk a month or two back about the copper/gold combination by the money of mine boys (and sometimes girl). Do any of the gold investors out there have any idea of how much more expensive gold recovery is when there's also copper involved. There can be its another $50/oz processing cost that in the who-cares, it won't change the economics category. There can be its another $500/oz which would matter. There its another $1,500/oz which might stuff up the economics completely. All can correctly be described as more costly. Any ideas where in that range the incremental cost of processing would sit when copper is also involved?