A report for the Australian Energy Market Operator found that NSW could have up to 85,000 petajoules of undeveloped gas resources. See page 15, Eastern and Southern Australia Existing Gas Reserves and Resources. This would be enough gas to meet 550 years of NSW’s current demand (156 petajoules per annum).
According to the Bureau of Resources and Energy Economics July 2012 Gas Market Report (p56), NSW imports 95% of its natural gas supply from other states.
Following a ruling by the Independent Pricing and Regulatory Tribunal (IPART) regulated NSW gas prices went up by 17.8% on July 1 2014. See this link.
See Australian consumption and production of natural gas, by state, physical units (Bureau of Resources and Energy Economics).