His Mt Albert neighbour was a P dealer on home detention and delivery or collection of the drugs was arranged by text messages between the pair.
Police became aware of the exchanges when the High Court granted a warrant to intercept electronic communications.
Cropper's lawyer Peter Davey argued convictions on such charges would be an "insurmountable" hurdle to gaining new employment - a consequence which grossly outweighed the gravity of the offending.
Mr Davey said it was particularly pertinent because Cropper worked in a very specialised area - IT law.
"[A conviction] would be the nail in the coffin for his future career in that legal sector," he said.
Cropper is set to start an intensive 18-week, residential rehabilitation programme starting next week to address his addiction.
Even before being charged, he had been attending Alcoholics and Narcotics Anonymous sessions up to five times a week, Mr Davey said.
However, Judge Ryan sided with police who opposed a discharge without conviction.
"If this was shoplifting . . . [ruling in favour of a discharge would] be fairly easy, but it's not," she said.
"A conviction for methamphetamine makes it very difficult to get a job, and so it should."
Judge Ryan described the drug as "a scourge on our community" and said Cropper had much more to do to address his addiction.
The consequences of a conviction were significant, she said, but the offending was deemed to be at a moderate level.
"This has been a brutal lesson for you," she said.
Intercepted text messages between Cropper and his neighbour - some of which were in the early hours of the morning - showed he had a penchant for the "clear rocky" meth rather than the "old school" version of the drug that he had previously tried.
Their relationship began when the defendant started buying food, cigarettes and other items for the man, for which he would be reimbursed or the costs would be taken off the price of his next hit.
In a letter penned to the court, Cropper made sweeping apologies to all involved and the judge accepted he was "clearly remorseful".
The court heard how the solicitor and barrister worked at Simpson Grierson for nine years before a seven-year hiatus when he practiced in the UK.
He had been back at the firm two years before he was charged.
In a profile piece pulled from the company website, Cropper said it was good to be back in New Zealand.
"I loved working and living in London and all the opportunities and travel it entails, but you really can't beat day to day life here," he said.
Cropper informed the New Zealand Law Society about the charges against him and its standards committee will decide whether he goes before the Lawyers and Conveyancers Disciplinary Tribunal where he could face further penalty.