Scott Snowden, 38, is said to have made the cash supplying cocaine in Helensburgh, Argyll and Bute, between 2009 and 2011.
However, prosecutors say Snowden only currently has £17,000 worth of assets available.
Crown office lawyers reckon he has money stashed in bank accounts and that he spent some of the money on jewellery.
The revelations emerged during a proceeds of crime hearing at the High Court in Edinburgh.
Crown Office lawyers are trying to seize the cash from Snowden, who was jailed with Robert Jennings, 50, for the murder of Thomas Sharkey, 55, Thomas Jr, 21, and eight-year-old Bridget in July 2013.
Snowden was jailed for a minimum of 33 years and Jennings was told he must serve at least 29 years in prison.
The pair set a fire which killed Mr Sharkey, Thomas Jr and Bridget at their home in Helensburgh. They were also convicted of trying to murder Mr Sharkey's wife Angela, 48, who survived the blaze.
In that case the court heard Mr Sharkey, who himself had previously served a prison term for drug dealing, was one of the people Snowden held a grudge against.
Snowden became enraged when Mr Sharkey intervened in a drugs debt that he was owed by the fire death victim's niece.
To exact his revenge, Snowden had the Mariners pub in Helensburgh, which was owned by Mr Sharkey, burned down. The blaze left Mr Sharkey in financial difficulty.
Snowden did not stop there, however, and ordered Jennings to set fire to Mr Sharkey's home.
Jennings carried out the act while Snowden was on a family holiday in Mexico, seemingly giving him the perfect alibi.
Once at the Sharkey home, at about 5am on July 24 2011, Jennings poured petrol through the letterbox of the only door to the house and set it alight before leaving the house.
The three people later died, leaving Angela as the only survivor.
The Crown is trying to use proceeds of crime legislation to recover cash from Snowden, who was jailed at Dumbar- ton Sheriff Court in December 2011 for 19 months for drugs offences.
Prosecution advocate Barry Divers told judge Lady Wise accountants estimate Snowden made more than £200,000 from his time selling narcotics.
However, the court heard that accountants have only been able to find £17,000 of assets in bank accounts and jewellery. Mr Divers told the court neither the Crown or Snowden's legal team were yet able to agree the sum that the drug dealer made from crime.
He asked Lady Wise to continue the case for another hearing which will take place at the High Court in Edinburgh on November 4, 2013.