A week or two back I saw a post by andy, on a google group, giving information about network roaming data charges.
You may view this
here if it interests you. See his post dated 26 Feb, 13:17
This brought to mind that I hadn't done much about comparing mobile broadband packages here, including costs for going over one's allowance, roaming charges, etc.
While I have it in mind to tackle this subject sometime, when I can get around to it, I have found a link which gives helpful comparisons at the bottom of its page.
See:-
http://www.broadband-expert.co.uk/mobile-broadband/It highlights the big variation in costs if you exceed monthly download limits, amongst other things.
