Police estimated the seized plants could produce millions of dollars each year if sold as "tinnies" at street level. But Karu provided an affidavit to Judge Sharp, which she described as "extremely honest", detailing the actual yield and profit, which was substantially less than first alleged.
According to Karu, the cultivation earned nearly $270,000 over a 21-month period from 14 harvests at two of the properties.
This was still large-scale commercial offending, Judge Sharp said.
One of the houses in Titirangi held four growing rooms, each with up to 80 plants, an area to dry cannabis flowers and another room to prepare the "buds" for sale.
A second cultivation system was found in a large garage complex on a rural section near Bethells Beach, which had one room with 40 plants.
Three other rooms were similarly set up, but held no plants.
Police searched a third property in Kelston and found a trapdoor which led to another cultivation system. Although no cannabis plants were found, police say two rooms were set up as crop nurseries with a separate compartment to dry the flowers.
Judge Sharp said Karu and Jensen were "in it up to their ears" in the commercial operation, which started from their own drug use.
She said both men were "extremely and unusually" remorseful and had gone to great lengths to rehabilitate themselves even before sentencing.
"I can, in all honesty, say that I seldom see real remorse which is so effectively communicated to a sentencing judge and which makes a sentencing judge believe in the expressions that are before her."
Both men had attended drug and alcohol courses and Karu told Judge Sharp that, having not known cannabis was addictive, he felt sick after meeting others under treatment.
Karu lives with his family in a 425sq m home on Northcote Pt, overlooking the Waitemata Harbour, with a 2008 capital value of $1.3 million. The Crown will seek to have the property forfeited under the Criminal Proceeds (Recovery) Act.
Operation Company
* Two cannabis nurseries and 370 plants found at properties in Titirangi and Bethells Beach.
* Hidden rooms found in two other properties in Kelston and Avondale.
* Jaak Roy Karu and Paul David Jensen pleaded guilty to cultivating, possessing for supply and selling Class-C drug.
* Admitted making $270,000 over two years.
* Each sentenced to 3 years in prison.
* Crown seeking forfeiture of Karu's $1.3 million home on North Shore.