Finding used high voltage power supplies

I'm trying to replace a Bertan 230-30R power supply that died recently, so I'm looking for something that can go form 0 to at least 30kV with a maximum current of 0.4mA. Higher maximum voltage, the ability to go from -30kV to +30kV, or both, would be nice but arn't really necessary. Does anyone have any recomendations on where to find something like this being sold used?