Judge Jonathan Down accepted some of the debate, and lowered the figure by about 400g.
Also sentenced yesterday was Napier woman Raewyn Marie Langridge, 39, who pleaded guilty to similar drugs charges but involving minimal amounts and less involved circumstances. Her term is 3 years and 6 months.
Summaries presented by the Crown prosecutor Clayton Walker, said that as part of the investigation in Hawke's Bay, police obtained search warrants enabling them to view cellphone records of suspects and conduct surveillance by intercepting mobile and landline phone calls.
Lawson was said to have made or organised at least 18 trips to Auckland for the purpose of buying methamphetamine, amounting to at least 40 ounces (1.13kg).
The investigation, Operation Spark, led to seven arrests in Hawke's Bay in August last year.
Another man awaits trial, as do others in the Auckland area who are alleged to be higher up the chain of command.