Unconventional Gas exploration is an expensive way to produce gas.
It requires high energy prices to make it viable. Therefore expanding Coal Bed Methane and Fracking for Shale Gas will not cause prices to fall significantly.
The cost of extraction alone may be higher than the current wholesale cost of gas partly because UK shale deposits are deeper and geologically more complex than those in the US, where gas prices have fallen.
The UK is part of a Worldwide gas market with prices set on this basis, unless supply of gas increases dramatically across the whole of Europe (not just the UK) gas prices will not fall significantly, at best any fall will only be 2-4%.
Unconventional Gas involves taking energy from a cheaper/low-value source of energy – electricity generated from coal and diesel fuel – and creating a higher value energy source – natural gas. It does nothing to improve the efficiency and sustainability of our energy systems.