The judicial Power of the United States, shall be vested in one supreme Court, and in such inferior Courts as the Congress may from time to time ordain and establish. The Judges, both of the supreme and inferior Courts, shall hold their Offices during good Behavior, and shall, at stated Times, receive for their Services a Compensation which shall not be diminished during their Continuance in Office.
Read the Constitution before calling something Un-Constitutional. Congress is mandated to pay the Judges and maintain the courts under the constitution.
While the Constitution mandates that justices be paid, it does not give the power to justices to determine how much and when, etc. they are compensated. This is a power given only to Congress. The response from the judiciary would be to simply refuse to hear cases or rule, which would make all federal laws unenforceable and thus render Congress impotent.