Just in case the man and presumably his grown up son on the park and ride bus back to EDF this evening are readers of NSC - you two are absolute pricks.
You stood in front of the last two available flip up seats on the bus while I was having an episode of Afib (irregular and massively high...
Martin Lewis's website has a useful guide here -
http://www.moneysavingexpert.com/family/gold-selling-sites
I've used Hatton Garden metals who are very reliable