OK, I'll bite!
Which caliber is it? They made these in 30RF or 32RF. 32RF is usually worth more since ammunition is simpler.
What's the bore like?
If you push forward on the trigger, from the bottom, while cocking the gun, does the gun stay cocked?
Is there a half ####? You can find out in the same operation: push forward on the trigger while gently and slowly cocking the hammer...
Does the firing pin rotate when you #### the hammer? You shouldn't need to push the trigger forward, each time the hammer goes all the way back and all the way forward again, the firing pin should rotate to the next barrel.
If you can answer us this, we can start getting more enthusiastic about guessing a price. Gunbroker and other online prices will help establish a range.