A researcher believes international drug smugglers are flooding the New Zealand market, bringing prices down and availability up.  The New Zealand Drugs Trends Survey found cocaine use is increasing, with 48% of respondents reporting they've used it at some point in their life.  It finds meth's also dropping in price, with a gram becoming 36% cheaper over the past six years.  Massey University drug researcher Chris Wilkins says the majority of Australia's meth comes from Mexican cartels.  He says there's now an overlap for smugglers, importing meth and cocaine together.  LISTEN ABOVE  See omnystudio.com/listener for privacy information.