Further to Dale's comment, if it was worth £X,XXX+ to you, its worth getting a tag, paying dale or aquanuke the setup fee' and then running your own dac and when needed.
As I understand it (yeah yeah yeah I still havent talked my partner into a tag, but I'm considering some waterboarding torture straight out guantanamo, to make him), that you pay your setup fee, first month, then you can shut off after a month and then pay a montly fee 4 months later, 8 months later to have it turned back on without the setup fee. (correct me if wrong). So if its worth enough then thats your end option