As luck would have it 'Practical
Boat Owner' (a UK magazine) has just published a complete list to marina costs for the UK. Some of the prices are not 100% accurate against my findings, but they are not a million miles away either.
At least it offers a good cost guide/league table and best of all it has all the telphone numbers.
Anyone planning a trip to and around the UK (also Ireland) may find it useful. If you can't get a copy of the newstands where you live then I believe you can download an e version from the publishers.
Thanks again everyone.