"Exciting News" From BT Openzone

For some reason, whenever I read "Exciting news" at the start of an email from BT I expect to be informed that a (not very well disguised) price hike is on it's way. On Thursday I got an email from BT with those exact words and I was not disappointed (wait a second, I was disappointed as it was the announcement of a price hike).

While I get to keep my current pricing plan until sometime next year, I will ultimately have to choose between one of BT Openzone's new price plans. The one that is 100% equivalent to the one I am on now is 10 pounds a month - a 100% price increase. I could go for the service that is the same cost as what I'm on now, and it's almost exactly the same but for one crucial difference - the minutes don't roam onto T-Mobile. With the 10 pound a month option, the 500 minutes do roam.

I've got sit down and do some calculations - do I go with the £5 or £10 a month service - or do I just drop BT Openzone altogether.