Find nimble during in search of a guide and decide if early gear or trading currency matters more to you. Killing him lets you loot professor kalancha's map and clear sky coordinates, plus his saiga d-12 shotgun and udp compact pistol from the body. Keep in mind though, taking him out means losing 2699 coupons that could've helped with early upgrades and equipment. Story stays the same either way, so dont worry about missing crucial content. Something interesting though - if youre feeling crafty, talk through all his dialogue first since some players manage to get both rewards by temporarily playing nice, grabbing the coupons, then dealing with him after. Mercenary types might prefer the immediate gear while traders benefit more from keeping him around, really depends on your style.