There is already a thread about 9 threads down from yours asking this exact same question. See it for replies. Are you looking at buying? If so, is it the gun in the other thread that's listed on the EE? It's listed at $175.00. $250.00 for an 840 would be for one in top condition with $200.00 being more like it. The model 84 usually brings more if the condition is there.
