Is it anymore expensive in the long run to have a pre-paid meter put in your flat rather than pay by direct debit. Through British Gas's error they presented me with a massive bill which I refused to pay. The have said that if they put a meter in they will relook at my previous bill.
I would have though for certain. you get a reduction bribe to allow companies access to your wealth and grab what they like, but pay a premium to use a meter.
On British Gas's Standard Tariff (using my own postcode to get a quote) the 'tariff comparison rate' is 5.26p per kWh when paid by direct debit or 5.58p on 'pay as you go', making 'pay as you go' 6.1% more expensive.