If I remember correctly, Asanko, Endeavour, Persues and B2Gold are all operating with AISC of $780, $709, $667 and $652 respectively with Persues and B2Gold's resources possibly the more similar to Namdini (based on indicated and inferred resource only).
So this US$800 figure could be closer to US$700...
Worth noting that Archie's suggested strip ratio of 2.5:1 is significantly lower than what i'm seeing with Persues (between 4:1 and 8:1). Perhaps someone can shed some light on the impact of this.
Also @flyboy77 to correct your post, POG is currently US$1260 or AUD$1575.