You could probably find a Carvin LB75F used for well under your budget. The fretless Carvins (as far as I know) all came with ebony fingerboards. I put a couple of coats of gunstock oil on my fingerboard and it really brought out a lot of the fretless buzz - combined with a careful setup. I always get compliments on the sound of my LB75F, more than any of my more expensive basses.
Rick B.
Rick B.