Yoou are looking at the wrong measure....look at return on investment, return on capital employed and I bet its about 1% - pretty awful and the future doesnt look good.
Look the price of sausages in the butchers is £1 a pound, cost 50p. The butcher has 1000 pounds in stock, enough for 10 days.
The meat suddenly rises to £1.50 a pound because of foot and mouth. If the butcher doesnt lift if his prices, what is going to happen - he doesnt generate enough cash to cover his meat purchases for the future.....result - insolvency.
The gas wholesale market is not set here in the UK - its a global market as gas can be shipped as LNG and also though pipelines - and also traded.
BG and the other competitors have to increase prices to maintain a semblance of profitability and an appropriate return to shareholders - not 30% - that would be excessive and arguments against price rises fully justified. More like 5 to 10% on capital employed...and that is no more than an average company on the stock market.