Justice Peter Callaghan told Marks that Queensland laws required him to spend at least two-and-a-half years in custody for charges involving the supply of shortened firearms. 

Shortened firearms are defined in Queensland as a rifle or shotgun that has been reduced in length to less than 75 centimetres. 

"If any good is to come of this, it is that word might spread of the penalties imposed for weapons offences," Justice Callaghan said.

The crown prosecutor said Marks over about seven months up to late October 2021 had sold mainly methamphetamine along with cannabis to at least 44 customers.

Marks dealt in relatively small amounts ranging from a 0.1 gram dose, known as a "point", up to six grams of meth at a time.

"The offending was serious due to the frequency of the drug supply, his supply of drugs on credit and his references to using a debt collector ... it is accepted the profits went mainly into his own drug consumption," the prosecutor said.

Defence barrister Daniel Boddice said Marks had demonstrated good behaviour in the two years since he was arrested.

"He can be a productive member of society, he can manage his addictions," Mr Boddice said.

Justice Callaghan said the decision was out of his hands.

Marks, of Alberton in the Gold Coast's rural north, was sentenced to four years' imprisonment to be suspended after serving two-and-a-half-years in custody. 

"It simply cannot be worth anyone's while to have anything to do with shortened weapons or any unauthorised dealing in firearms, the penalties are so severe," the judge said.