Thanks guys. A lot of ideas to ponder. Much of what was said here was also said by the guy at the bike shop today.
One surprising thing he said was trials is all but "dead". Said they had three bikes in the back that they can't sell. Suggested my son was probably wanting to do BMX freestyle. And BMX bikes were much easier to sell so if we find out it is not what he wants to do, we would not be stuck with an unsellable bike.