Odds are very, very long of ever finding one on the boards. There are ~1000 different black refs ever made, and I rarely get a nibble when looking for anything, let alone a specific player. The name of the game with black refs is patience. One will be listed sometime, just hold out til then. I will let you know as soon as I see one pop up, I search pretty often.
Just to be safe, I would keep $50 set aside for one, but you should be able to scoop it up for half that. I paid $12.50 dlvd for mine.
To tide you over, you can buy a ref /561 for a buck or two, sharpie the edges, and make sure nobody looks at the back of the card. Would be a dead ringer for this guy: