i just turned 16, brownies are a good gift, there so tasty and shows creativity than as compared to buying a gift card
you can ask him what he really like in a unawareness way, and then surfing on the internet for the wholesale products which is good and cheap for you. you can consider the china wholesale products as the low price man power and cheap original materials.
it really depends on the guy, does he play video games most guys around that age do. If so go to game stop and ask for a good game for his game console.
Get him like a shirt,or a if he wears base ball cap get him one :)