DeFeet Woolie Boolie cycling socks. They are the bestest in cold weather, and you can buy them for about $10.

Cage Rocket for storing gear in a water bottle cage, also costs about $10.

Brass bell (I've got a nice Incredibell) if your friend is a commuter, but otherwise he will probably thing it's Freddish. Less than $10.

Some new bar tape. I like Cinelli cork, and it comes in lots of colors.