Our fixed rate finished a couple of years ago and we have never re-mortgaged, our payments haven't changed at all. I don't think rates will change much if, they did half the country would be at risk of loosing their homes in this current climate - stoopid government
The the others have said I think it depends a lot on your future financial position. Interest rates are so low atm the only way they can go is up so you need to think about how high could you afford for it to go if you went for a variable.
The fees for the variable sounds extortionate to me Are there any early redemption penalties as well?
We always fix our rate when the time comes. It's easier for us to know what's coming out each month. When the intrest rates rose a few years back we would have been in trouble if we hadn't had it fixed. Best thing now is that we don't have to pay the fee to fix it as our mortgage is under the threshold