Being a Pedersolli that is a fine musket. 75 caliber... that is a big hole. There are written reports where in the Revolutionary war, as the soldiers stood in formation, the ball from a Bess would penetrate up to three people. Two was very common. Just a lot of horse power there. I have heard they make a somewhat good shotgun too. As for the value.. like Semisane said.. $900.00 new so used would be at least 50% of that or more. Depending on condition.