[locksley]

At the moment I'm filtering out items 2 standard deviations out of the median. It catches the ridiculous cases, i.e. when some fool tries to get away with selling an iphone for $6000 (yes I've seen this before).

Perhaps I need to filter it within 1 or 1.5 stdevs. Will experiment with this.

However, sometimes you can easily see there are two clusters of results. Not sure how to mathematically determine this. Any ideas?