Under-18s will be banned from buying knives, raising the age limit from 16 while NSW Police will get new powers to search people for blades in response to the alleged stabbing of an Assyrian bishop in Wakeley and the Bondi Junction massacre.   A new $400 bonus for an estimated 700,000 Victorian students will be unveiled as the key cost of living measure in today’s state budget.    The state government has spent more than $111m buying properties and doing technical studies for a renewable energy project that has no business case, is not backed by the Opposition and is vehemently opposed by locals.   A third of primary school students and almost half of high schoolers have sought, or are planning to start, treatment for mental health concerns.  See omnystudio.com/listener for privacy information.