Simplest way would really to look at this like he "Might":
If he's into his decks, but suffers from the lack of records then you might want to try and get him a white label in what ever music genre he likes.
(Of course that means trecking to a record shop or hunting down one of those "Just released but not known" labels where you have to spin them on the shops decks and listen closely to see if it's any good)
If he's into his X-Box totally, then you ould go out and buy a game. This might please him or you might be secretly feeding the child within.
You could try grabbing a movie, I don't think there are that many decent ones out on release recently, so you might want to go RETRO. Hunt down a classic film that feeds a secret genre.
(I can't tell you what here, but I ended up Genreing on War Games, 13th Floor, Frequency, Anti-trust, Matrix etc.)
You could take him out for something on his birthday if nobody else has, of course this might be a bit more a personal issue.
Sort of things you can do... use your imagination, as not everything has to cost the contents of Fort Knox.
(Picnics, movies, concerts, theatres etc)
[You could push some form of culturing lol]
JUST DON'T GET HIM SOCKS!