The court was told he once offered his mates $25 an hour to find four ounces of lower quality speed, worth $11,000, after he forgot where he buried it at the beach.
Miller would cut down the speed with epsom salts so he could sell more. He also sold drugs at music festivals.
The court heard his mates owed him $35,000 for drugs he had supplied.
Crown prosecutor David Finch said Miller had a "significant customer base" and a "high-volume turnover".
He said Miller had six times sold a total $11,200 worth of drugs to a covert officer who befriended him in 2010-11, which is when police had tapped three of the accused's mobiles.
"(Miller) had access to high-quality drugs and significant amounts of drugs, and showed a preparedness to supply larger amounts to expand his business," he said.
Defence barrister Julie Sharp said Miller's business mostly involved "dealing to other drug addicts, many of which were his friends".
She said Miller had recognised he had to change his life, noting he independently sought help from a drug counsellor, and sought work in Western Australia to get away.
"He was taking steps to extricate himself from the drug scene on the Sunshine Coast," she said.
Ms Sharp said her client - who grew up in New Zealand with a violent drug-addicted father followed by a drug and gambling addicted stepfather - was left to fend for himself from age 15 when his mother moved to Australia without him.
Ms Sharp said she could not tell the court Miller had been abstinent from drugs since his arrest but he had been trying - noting he had held down jobs in Western Australia and scaffolding work until he had a car crash which left him on welfare.
Justice Ros Atkinson said Miller was "obviously a significant dealer in drugs on the Sunshine Coast".
BY THE NUMBERS
Speed: Caught with 255g, 10.6 per cent purity. Received four ounces (113g) each fortnight for $11,000 on credit and then would have to repay his suppliers. Once swapped two ounces (57g) for a motorcycle which he later advertised online for $9000. Could access pure speed for $14,000 an ounce (113g).
Ecstasy: Caught with 1000 tablets at 30 per cent purity. Could turnover 2000 pills in a weekend, buying them for $11 each and selling them for $14 or $15.
GHB: Selling the drug in large quantities at $2-2.50 a ml or $1500 for a bottle.
Cocaine: Selling $1000 worth a week.