many years ago, Santa Cruz made a deck that was fiberglass with a foam core. It was horribly expensive, and like some of the other posters said, first nose into a curb, and it's history. Boards have been heavier and lighter over the years, and have remained pretty resilient, except for a patch in 90-91 when they were so ridiculously thin they snapped like twigs. Skaters thought that this was funny, as you could "focus" someone's deck by stomping on the middle. Of course this was in many a skate video, resulting in a very expensive habit. The gradual wear down of the tail and nose is something else that sets rock maple apart from synthetics-it just does the job better. The suggestion of shop decks, or any producers "blank" deck would be a good option. I would look at a few decks of your son's and try to figure out why they're breaking- this may be difficult to do without some years of experience. I've been skating since 85-86, and loved it, so kudos to you. Skateboarding is a great hobby, and keeps many a youth out of trouble (like me). I'd even go so far as to say that I'd pay the dough to keep my kid in skating (obviously within reason). Man, I should go grab one of my boards now, but the neighborhood skate rats are outside..
A few companies had experimented with "slicks" or other materials as a bottommost layer glued onto the deck- I have one of the Firm Decks (ray barbee) that has this, and I've owned that deck for~12 years. Hell, I still skate on it.
Maybe he should pay for his own, but I would hate to see him stop skating for lack of money and get into something that will inevitably be more expensive.
"Original Bones Brigade" fan and lifetime Indy rider, Joe