You could always go self-catering in England for a reasonable amount. For example you can spend a wet week in Cornwall in a mobile home. Another relatively good value option is to hire a boat and explore the waterways of Britain, again mostly self catering if you wish. And there is always sleeping under canvas and with modern tents you can have a fair degree of luxury and a bit of an adventure for children.

If you want a cheap holiday there are actually plenty of choices in Britain, and with a low value of the pound, they are better value in comparison to the continent than they were a couple of years ago.

We are very lucky living in the British Isles to have such wonderful scenery in the Scottish Highlands, but if it were any closer to London it would have been ruined by now. Personally I would recommend visiting the Highlands at least once. It is a little more expensive that a package holiday to Costa Brava, but if you get good weather it is a magical place. (Children won't like it as they don't appreciate scenery or walking).