New gear box shell vs 2nd hand donor gun
 

Have a king arms m4a1 that has half of the gear box broken. New gear box shell is aprox 50-60 bucks but I can get a used m4 for 80-90 bucks. What is the better option?

80-90 for an m4? maybe the extra money worth the extra parts you get. the best option is to get age verified and check the classifieds for cheaper options