The /bonus Rhino Hammer severely deflates the price of all pre hammers...
I have a 15-24 14^50 collecting dust because it's too hard to find a collector for me. It's gotta be worth at least some black dye though. These hammers don't just drop every day. Your hammer's rare. Maybe if you find a rich die-hard pre item collector? Or someone who's wealthy enough, doesn't have the /bonus rhino hammer, and has a warrior that he/she wants to try going ham on...? [too many variables... I know >.<] It'll be tough getting good money for it. It's a rock and a hard place!
Minimum [1-3BD] is my best educated guess.
Could be more if someone's a collector that doesn't yet have the near-perfect hammer/skin in pre and wants a hammer like yours.