Interest rates nailed to the floor by the Reserve Bank and a surging house price boom have done for the NSW government what Chinese iron ore buyers did for the federal government budget fortunes. Stamp duty and a fully reopened state have helped deliver NSW Treasurer Dominic Perrottet a deficit in Tuesday’s budget of just half the $16 billion feared last November. Like the federal windfall it has been spent promptly, on health, big public service pay rises, electric car incentives, and an extravagant and superfluous $70 million giveaway on vouchers for hotel stays and Friday lunches in Sydney’s CBD.