How much does it cost to expunge a possession of marijuana felony?

You need to call the Common Pleas Court in your county; The clerk's office can tell you what the fee will be;

Different lawyer charge different amounts. You can only expunge a case after the statute of limitations has run or if the DA agrees before. Also, the case must have been dismissed or you were found not guilty after a trial or you were no-billed by a grand jury.