This link might help you.
http://www.moneysavingexpert.com/family/free-cheap-wills
Me and the wife are in the process of writing our first wills for when she falls doon the stairs. We opted for Which magazine - cost £50 for the two of us and gives you access to their team of lawyers for a month - nae bad - but be quick as the offers expires at the end of this month.
http://willsoffers.which.co.uk/mls