Can't hurt to school him in the basics first - learn to shoot with open sights. Not saying he should be a marksman with open sights, but just to learn the basics of proper sight
alignment, etc. When he can put 4rounds into a 4" target at 100yds., then get the scope
(if he wants one). If nothing else, he'll learn how to use the sights, and that they could be used for backup in the rare event of scope failure in the field.