If the kid really wants something new and doesn't have the budget for a Yamaha, I've played the Orion horns and liked them. I don't know how well it would hold up to marching band or long term.
I would STRONGLY consider doing a rental from your local shop. They'll have quality horns, monthly rates, and come with maintenance agreements. Most of the time you can return the horn at the end of marching season if he's done with it, or if he wants to stick with saxophone he can trade it in for an upgrade.