I am selling a zombie spawner, it is on smp5, It is just the spawner, no grinder built, P.M. me with offers, asking 10K, price negotiable. http://empireminecraft.com/threads/guide-selling-mob-spawner-locations.9738/
if you need help making it into a grinder and selling it for more then i think i can help. Also, my information might be wrong, but i think i saw on another thread like this that it might have been banned to sell spawners and grinders? im not quite sure but just to let you know.
You must link here in the op http://empireminecraft.com/threads/guide-selling-mob-spawner-locations.9738/