This weapon is amazingly powerful, you can reuse ammo over and over so I think it is pretty efficient. The one I got costed around 60 dollars, it shoots 6 inch bolts that really pack a punch with 110 full pounds of energy upon the target. It is similar to what a 22. long rifle rimbolt cartridge would do, and at a 150 feet per second. You can also shoot explosive arrows too, it will go straight through a watermelon. Ammo is cheap usually 10 bolts for 6 dollars.