When I've cited other sales and articles in the past, it is has never resulted in a sale for me. The people who require convincing probably do not have any real budget. Also most of the time it is easy to pick holes in the data, e.g. if hardware.com.au is worth $33,000 it would be easily argued that the domain they are inquiring about is worth nothing or very little.
That said I still cite dnjournal sometimes but really it is probably a waste of time.