The Department for Transport initially estimated the cost of first section, from London to Birmingham, at between £15.8 and £17.4 billion, and the entire Y-shaped network between £30.9 and £36 billion, not including the Manchester Airport station which would be locally funded. In June 2013 the projected cost (in 2011 prices) rose by £10 billion to £42.6 billion, with an extra £7.5 billion budgeted for rolling stock for a total of £50.1 billion. Less than a week later, it was revealed that the DfT had been using an outdated model to estimate the productivity increases associated with the railway. In 2014, the most commonly cited cost applied to the project was £56.6 billion, which corresponds to the June 2013 funding package, as adjusted for inflation by the House of Lords' Economic Affairs Committee in 2015. Over sixty years, the line was estimated to provide £92.2 billion of net benefits and £43.6 billion in new revenue; as a result, the benefit–cost ratio of the project was then estimated to be 2.30; that is, it is projected to provide £2.30 of benefits for every £1 spent.